Income Taxes (Schedule of Defered Income Tax Assets and Liabilities) (Details) - USD ($)	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Deferred tax assets:
Net operating loss carryforward	$ 9,033,235	$ 7,163,547
Allowance for doubtful accounts (recovery)	181,774	105,122
Deferred rent	180,154	20,574
Stock-based compensation	954,586	687,067
Contributions carryforward	60	60
Total deferred tax assets	10,349,809	7,976,370
Deferred tax liabilities:
Property and equipment	(234,336)	(132,042)
Intangibles	(64,439)	(6,573)
Total deferred tax liabilities	(298,775)	(138,615)
Deferred tax assets, net	10,051,034	7,837,755
Valuation allowance:
Valuation allowance	(10,051,034)	(7,837,755)	$ (9,471,662)
Net deferred tax asset