Tokenize whitespace strings correctly

[ssured]

Tokenizing " hello" (note leading space) currently results in 2 tokens: ["","hello"]. Should be ["hello"]. See PR for fix

[pangratz]

Seems like a good change! 👍

@ssured I've opened a PR to add a basic test ssured#1

[olivernn]

Thanks for this, your fix has been included in version 0.3.0