Note 8 - Convertible Notes Payable (Details Textual) - USD ($) | Mar. 23, 2020 | Jul. 17, 2019 | May 21, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Jun. 23, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Proceeds from Convertible Debt | | | | $ 100,000 | $ 323,726 | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | | | | $ 0.52 | | | | $ 1.95 | |
Warrants Issued in Connection Amendment of Notes Payable [Member] | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | | | | | | 115,385 | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | | | | $ 0.01 | | $ 0.01 | | | |
Convertible Notes Payable Issued May 21, 2019 [Member] | | | | | | | | | |
Debt Instrument, Face Amount | | | $ 550,000 | | | | | | |
Convertible Notes Payable, Total | | | $ 500,000 | | | | | | |
Debt Instrument, Discount Rate | | | 10.00% | | | | | | |
Debt Instrument, Interest Rate, Stated Percentage | | | 8.00% | | | | | | |
Debt Instrument, Term (Day) | | | 180 days | | | | | | |
Debt Instrument, Redemption Premium After 91 Days | | | 115.00% | | | | | | |
Proceeds from Convertible Debt | | | $ 350,000 | | | | | | |
Debt Instrument, Convertible, Conversion Price (in dollars per share) | | | $ 1.95 | | | | | | |
Debt Instrument, Convertible, Percentage of Lowest Bid Price During Prior 15 Consecutive Trading Days | | | 65.00% | | | | | | |
Debt Instrument, Redemption Fee, Amount | | | | | | | $ 57,750 | | |
Debt Instrument, Convertible, Beneficial Conversion Feature | | | $ 207,308 | | | | | | |
Convertible Notes Payable Issued May 21, 2019 [Member] | Embedded Derivative Financial Instruments [Member] | | | | | | | | | |
Derivative Liability, Total | | | | $ 365,445 | | | | | |
Convertible Notes Payable Issued July 17, 2019 [Member] | | | | | | | | | |
Debt Instrument, Face Amount | | $ 165,000 | | | | | | | |
Convertible Notes Payable, Total | | $ 150,000 | | | | | | | |
Debt Instrument, Discount Rate | | 10.00% | | | | | | | |
Debt Instrument, Interest Rate, Stated Percentage | | 8.00% | | | | | | | |
Debt Instrument, Term (Day) | | 180 days | | | | | | | |
Debt Instrument, Convertible, Conversion Price (in dollars per share) | | $ 1.95 | | | | | | | |
Debt Instrument, Convertible, Percentage of Lowest Bid Price During Prior 15 Consecutive Trading Days | | 65.00% | | | | | | | |
Debt Instrument, Convertible, Beneficial Conversion Feature | | $ 135,000 | | | | | | | |
Debt Instrument, Redemption Premium, Between 91 and 180 Days | | 115.00% | | | | | | | |
Convertible Notes Payable Issued July 17, 2019 [Member] | Embedded Derivative Financial Instruments [Member] | | | | | | | | | |
Derivative Liability, Total | | | | 156,620 | | | | | |
Convertible Notes Payable One Issued March 23, 2020 [Member] | | | | | | | | | |
Proceeds from Convertible Debt | $ 75,000 | | | | | | | | |
Convertible Notes Payable Two Issued March 23, 2020 [Member] | | | | | | | | | |
Proceeds from Convertible Debt | 25,000 | | | | | | | | |
Convertible Notes Payable Issued March 23, 2020 [Member] | | | | | | | | | |
Debt Instrument, Face Amount | $ 100,000 | | | | | | | | |
Debt Instrument, Interest Rate, Stated Percentage | 52.00% | | | | | | | | |
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ 0.60 | | | | | $ 1.95 | | | |
Debt Instrument, Covenant, Not Converted Before Maturity, Conversion, Unconverted Principle Per Warrant Share | | | | | | $ 0.8666 | | | |
Convertible Notes Payable Issued March 23, 2020 [Member] | Embedded Derivative Financial Instruments [Member] | | | | | | | | | |
Derivative Liability, Total | | | | $ 45,756 | | | | | |