Note 6 - Equity (Details Textual) | Dec. 14, 2017USD ($) | Oct. 31, 2017USD ($)$ / sharesshares | Sep. 30, 2017USD ($)$ / sharesshares | Aug. 31, 2017USD ($)$ / sharesshares | Mar. 31, 2017USD ($)$ / sharesshares | Feb. 28, 2017USD ($)$ / sharesshares | Dec. 31, 2017USD ($)$ / sharesshares | Dec. 31, 2016USD ($)$ / sharesshares | Dec. 18, 2017$ / sharesshares | Mar. 09, 2017 | Feb. 17, 2017$ / shares | Feb. 28, 2016$ / sharesshares | Dec. 31, 2015$ / shares | Nov. 30, 2015shares |
Stock Issued During Period, Value, New Issues | | | | | | | $ 2,191,927 | $ 2,177,801 | | | | | | |
Shares Issued, Price Per Share | $ / shares | | | | | | | $ 3 | $ 1.25 | | | | | | |
Payments of Stock Issuance Costs | | | | | | | $ 169,472 | $ 204,700 | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | $ 1.86 | $ 1.53 | | | | | $ 1.44 | |
Stock Issued During Period, Shares, Issued for Services | shares | | | | | | | 100,000 | 20,000 | | | | | | |
Stock Issued During Period, Value, Issued for Services | | | | | | | $ 300,000 | $ 25,000 | | | | | | |
Class of Warrant or Right, Exercised During Period | shares | | | | | | | 790,000 | | | | | | | |
Incentive Fees | | | | | | | $ 926,885 | | | | | | | |
Proceeds from Related Party Debt | | | | | | | 1,100,000 | | | | | | | |
Accretion Expense | | | | | | | $ 15,468 | $ 122,631 | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | shares | | | | | | | 440,000 | 2,915,000 | | | | | | |
Equity Incentive Plan 2015 [Member] | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | shares | | | | | | | | | | | | | | 4,000,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | shares | | | | | | | 440,000 | 2,915,000 | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | | | | | | | $ 455,046 | $ 1,842,233 | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period | shares | | | | | | | 30,000 | 160,000 | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate | | | | | | | 0.00% | 0.00% | | | | | | |
Equity Incentive Plan 2015 [Member] | Minimum [Member] | | | | | | | | | | | | | | |
Share Price | $ / shares | | | | | | | | $ 0.63 | | | | | | |
Equity Incentive Plan 2015 [Member] | Maximum [Member] | | | | | | | | | | | | | | |
Share Price | $ / shares | | | | | | | | $ 1.25 | | | | | | |
Equity Incentive Plan 2015 [Member] | Employee Stock Option [Member] | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Payments | | | | | | | $ 0 | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum | | | | | | | 1.10% | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum | | | | | | | 1.30% | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term | | | | | | | 5 years | | | | | | | |
Allocated Share-based Compensation Expense, Total | | | | | | | $ 124,415 | $ 1,783,542 | | | | | | |
Equity Incentive Plan 2015 [Member] | Employee Stock Option [Member] | Minimum [Member] | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate | | | | | | | 146.00% | | | | | | | |
Equity Incentive Plan 2015 [Member] | Employee Stock Option [Member] | Maximum [Member] | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate | | | | | | | 148.39% | | | | | | | |
Unsecured Promissory Note [Member] | | | | | | | | | | | | | | |
Debt Instrument, Unamortized Discount, Total | | | | | | | $ 18,652 | | | | | | | |
Employee [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | | 40,000 | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | $ 4.50 | | $ 2 | | | $ 1.50 | | | |
Proceeds from Warrant Exercises | | | | | | $ 60,000 | | | | | | | | |
Warrants and Rights Outstanding | | | | | | $ 46,000 | | | | | | | | |
Warrants and Rights Outstanding, Term | | | | | | 5 years | | | | | | | | |
Class of Warrant or Right, Exercised During Period | shares | | | | | | 40,000 | | | | | | | | |
Director [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | 50,000 | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | $ 3 | | | | | | | | | | | |
Warrants and Rights Outstanding, Term | | | 5 years | | | | | | | | | | | |
Director [Member] | Promissory Note [Member] | | | | | | | | | | | | | | |
Proceeds from Related Party Debt | | | $ 500,000 | | | | | | | | | | | |
Debt Instrument, Unamortized Discount, Total | | | 52,166 | | | | | | | | | | | |
Accretion Expense | | | | | | | 8,718 | | | | | | | |
Proceeds from Issuance of Long-term Debt, Total | | | $ 500,000 | | | | | | | | | | | |
Investor [Member] | Unsecured Promissory Note [Member] | | | | | | | | | | | | | | |
Proceeds from Related Party Debt | $ 200,000 | | | | | | | | | | | | | |
Debt Instrument, Unamortized Discount, Total | $ 18,652 | | | | | | | | | | | | | |
Accretion Expense | | | | | | | 434 | | | | | | | |
Employee [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | 10,000 | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | $ 3 | | | | | | | | | | |
Warrants and Rights Outstanding, Term | | | | 5 years | | | | | | | | | | |
Employee [Member] | Promissory Note [Member] | | | | | | | | | | | | | | |
Proceeds from Related Party Debt | | | | $ 100,000 | | | | | | | | | | |
Debt Instrument, Unamortized Discount, Total | | | | 10,435 | | | | | | | | | | |
Accretion Expense | | | | | | | 1,844 | | | | | | | |
Proceeds from Issuance of Long-term Debt, Total | | | | $ 100,000 | | | | | | | | | | |
Rio Vista [Member] | Unsecured Promissory Note [Member] | | | | | | | | | | | | | | |
Proceeds from Related Party Debt | | $ 500,000 | | | | | | | | | | | | |
Debt Instrument, Unamortized Discount, Total | | 50,229 | | | | | | | | | | | | |
Accretion Expense | | | | | | | $ 4,472 | | | | | | | |
Proceeds from Issuance of Long-term Debt, Total | | $ 500,000 | | | | | | | | | | | | |
Fully Vested, Non-forfeitable Warrants [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | | | | 10,000 | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | | $ 1.25 | | | | | | |
Warrants and Rights Outstanding | | | | | | | | $ 11,899 | | | | | | |
July 16, 2015 Warrants [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | $ 1.50 | | | | | | | | | |
Proceeds from Warrant Exercises | | | | | $ 525,000 | | | | | | | | | |
March 1, 2017 Warrants [Member] | | | | | | | | | | | | | | |
Stock Issued During Period, Shares, New Issues | shares | | | | | 350,000 | | | | | | | | | |
New Smith Warrant [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | 350,000 | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | $ 4.50 | | | | | | | | | |
Warrants and Rights Outstanding | | | | | $ 402,000 | | | | | | | | | |
New Smith Warrant [Member] | Measurement Input, Expected Dividend Rate [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | 0 | | | | | | | | | |
New Smith Warrant [Member] | Measurement Input, Price Volatility [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | 148.4 | | | | | | | | | |
New Smith Warrant [Member] | Measurement Input, Risk Free Interest Rate [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | 1.89 | | | | | | | | | |
New Smith Warrant [Member] | Measurement Input, Expected Term [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | 5 | | | | | | | | | |
February 19, 2016 Warrants [Member] | Diamond B Capital, LLC [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | | | | | | | | 400,000 | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | $ 1.50 | | | | | | | $ 2 | | |
Proceeds from Warrant Exercises | | | | | $ 600,000 | | | | | | | | | |
Warrants and Rights Outstanding, Term | | | | | | | | | | | | 5 years | | |
Class of Warrant or Right, Exercised During Period | shares | | | | | 400,000 | | | | | | | | | |
February 19, 2016 Warrants [Member] | Diamond B Capital, LLC [Member] | Director [Member] | | | | | | | | | | | | | | |
Related Party Transaction, Ownership Percentage | | | | | | | | | | | | 12.00% | | |
New Diamond B Warrant [Member] | Diamond B Capital, LLC [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | 400,000 | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | $ 4.50 | | | | | | | | | |
Warrants and Rights Outstanding | | | | | $ 463,000 | | | | | | | | | |
New Diamond B Warrant [Member] | Measurement Input, Expected Dividend Rate [Member] | Diamond B Capital, LLC [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | 0 | | | | | | | | | |
New Diamond B Warrant [Member] | Measurement Input, Price Volatility [Member] | Diamond B Capital, LLC [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | 148.4 | | | | | | | | | |
New Diamond B Warrant [Member] | Measurement Input, Risk Free Interest Rate [Member] | Diamond B Capital, LLC [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | 1.89 | | | | | | | | | |
New Diamond B Warrant [Member] | Measurement Input, Expected Term [Member] | Diamond B Capital, LLC [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | | | | | | 5 | | | | |
Warrant to Employee 2 [Member] | Employee [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Term | | | | | | 5 years | | | | | | | | |
Warrant to Employee 2 [Member] | Measurement Input, Expected Dividend Rate [Member] | Employee [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | | 0 | | | | | | | | |
Warrant to Employee 2 [Member] | Measurement Input, Price Volatility [Member] | Employee [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | | 148.4 | | | | | | | | |
Warrant to Employee 2 [Member] | Measurement Input, Risk Free Interest Rate [Member] | Employee [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | | 2.05 | | | | | | | | |
Warrant to Employee 2 [Member] | Measurement Input, Expected Term [Member] | Employee [Member] | | | | | | | | | | | | | | |
Warrants and Rights Outstanding, Measurement Input | | | | | | 5 | | | | | | | | |
Warrants Issued for Services [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | | | 890,000 | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | $ 3 | | | | | | | |
Adjustments to Additional Paid in Capital, Warrant Issued | | | | | | | $ 1,019,855 | 11,899 | | | | | | |
Warrants and Rights Outstanding | | | | | | | $ 1,019,855 | | | | | | | |
Warrants and Rights Outstanding, Term | | | | | | | 5 years | | | | | | | |
Warrants Issued to an Investor [Member] | Investor [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | | | | | 50,000 | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | | | $ 3 | | | | | |
Warrants and Rights Outstanding, Term | | | | | | | | | 5 years | | | | | |
Warrants Issued to Rio Vista [Member] | Rio Vista [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | 50,000 | | | | | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | $ 3 | | | | | | | | | | | | |
Warrants and Rights Outstanding, Term | | 5 years | | | | | | | | | | | | |
Private Placement [Member] | | | | | | | | | | | | | | |
Stock Issued During Period, Value, New Issues | | | | | | | | $ 10,000,000 | | | | | | |
Shares Issued, Price Per Share | $ / shares | | | | | | | | $ 3 | | | | | | |
Stock Issued During Period, Shares, New Issues | shares | | | | | | | 787,133 | 221,667 | | | | | | |
Proceeds from Issuance of Private Placement | | | | | | | $ 2,361,399 | $ 665,001 | | | | | | |
Payments of Stock Issuance Costs | | | | | | | $ 169,472 | $ 53,200 | | | | | | |
Private Placement [Member] | Fully Vested, Non-forfeitable Warrants [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | | | 50,409 | 11,083 | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | $ 3 | $ 3 | | | | | | |
Adjustments to Additional Paid in Capital, Warrant Issued | | | | | | | $ 46,000 | $ 11,000 | | | | | | |
October 2015 Private Offering [Member] | | | | | | | | | | | | | | |
Shares Issued, Price Per Share | $ / shares | | | | | | | | $ 1.25 | | | | | | |
Stock Issued During Period, Shares, New Issues | shares | | | | | | | | 1,374,000 | | | | | | |
Proceeds from Issuance of Private Placement | | | | | | | | $ 1,717,500 | | | | | | |
Payments of Stock Issuance Costs | | | | | | | | $ 151,500 | | | | | | |
Share Price | $ / shares | | | | | | | | $ 2 | | | | | | |
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right | shares | | | | | | | | 1 | | | | | | |
October 2015 Private Offering [Member] | Fully Vested, Non-forfeitable Warrants [Member] | | | | | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares | | | | | | | | 152,575 | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | | | | | | | | $ 2 | | | | | | |
Adjustments to Additional Paid in Capital, Warrant Issued | | | | | | | | $ 153,000 | | | | | | |