Note 8 - Equity - Warrant Activity (Details) - Warrant [Member] - USD ($)	9 Months Ended	12 Months Ended
	Mar. 31, 2018	Jun. 30, 2017
Warrants outstanding (in shares)	4,150,535
Warrants outstanding, weighted average exercise price per share (in dollars per share)	$ 4.67
Warrants outstanding, weighted average remaining contractual life (Year)	3 years 149 days	3 years 317 days
Warrants outstanding, aggregate intrinsic value		$ 42,582
Warrants issued (in shares)
Warrants issued, weighted average exercise price per share (in dollars per share)
Warrants expired (in shares)	(691,709)
Warrants expired, weighted average exercise price per share (in dollars per share)	$ 8.68
Warrants outstanding (in shares)	3,458,826	4,150,535
Warrants outstanding, weighted average exercise price per share (in dollars per share)	$ 3.65	$ 4.67
Warrants exercisable (in shares)	3,403,270
Warrants exercisable, weighted average exercise price per share (in dollars per share)	$ 3.51
Warrants exercisable, weighted average remaining contractual life (Year)	3 years 167 days
Warrants exercisable, aggregate intrinsic value