wakatime 2.1.6 (new formula)

Adding new formula for wakatime
Did you remove `bin.env_script_all_files(libexec+"bin", :PYTHONPATH => ENV["PYTHONPATH"])`? That line's still necessary, after the `bin.install` statement above. Sorry if I was unclear! If that's not the fix, can you push a (failing) formula so I can take a look at the whole thing at once? Lots of moving parts in our Python support. :/