Fair value of financial instruments (Details) - USD ($)
May 31, 2019
Feb. 28, 2019
Fair Value Of Financial Instruments Details Abstract    
Warrants (First Issuance), carrying amount $ 219,531
Warrants (First Issuance), fair value 219,531
Long-term debt, carrying amount 965,969 1,005,518
Long-term debt, fair value 965,969 1,005,518
Convertible notes (First Issuance), carrying amount   2,495,636
Convertible notes (First Issuance), fair value   2,650,000
Convertible notes (Second Issuance), carrying amount 3,556,249 3,126,886
Convertible notes (Second Issuance), fair value $ 4,900,000 $ 3,150,000