Summary of Significant Accounting Policies (Tables)

3 Months Ended

Jul. 31, 2019

Schedule of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended
	July 31,
	2019	2018
Customer A	–%	10%

	July 31,	April 30,
	2019	2019
Customer B	15%	13%

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

		July 31,			April 30,
		2019			2019
Balance of allowance for doubtful accounts, beginning of period	$	619,514		$	322,638
Bad debt provision		50,861			1,082,440
Write-off of receivables		(247,480	)		(785,564	)
Balance of allowance for doubtful accounts, end of period	$	422,895		$	619,514