Allow input options without values

[Aryk]

Work was done here 2 years ago: #156

Any chance we can merge this into the main version deployed on rubygems?

I'm on "3.0.2" which I believe is the latest, yet I don't have this change.

[Aryk]

This is the only gem in my library out of 50 that I have to pull from a git repository.. 😢