Fix #417

[hoelzro]

This adds a test and a fix for #417

[olivernn]

How does this handle strings that have trailing white space?

I think the simplest approach is to just remove String#trim lib/tokenizer, both leading and trailing white space should be ignored by the check on line 46.

It'd be good to have a test for both the leading and trailing white space to verify we've covered both cases.

[olivernn]

Thanks for taking a look into this, I think the change required to fix this is even simpler though...

[hoelzro]

@olivernn Thanks for the feedback - I've just made the changes you requested and pushed them up to my fork!