Note 10 - Fair Value Measurements and Other Financial Instruments - Summary in Changes in Fair Value (Details) - USD ($)	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Balance, beginning of period	$ 1,323,625
Change in fair value of derivative liabilities	(508,624)	$ (773,000)
Balance, end of period	815,001
Warrant [Member]
Balance, beginning of period	505,069
Change in fair value of derivative liabilities	(64,333)
Balance, end of period	440,736
Convertible Notes [Member]
Balance, beginning of period	818,556
Change in fair value of derivative liabilities	(444,291)
Balance, end of period	$ 374,265