bugfix: wrong indexing in branch detecting

[BeastyBlacksmith]

I supposed your intention was to allow multiple spaces between package and version. Otherwise the version_pos2 can be replaced by version_pos.

[johnnychen94]

Thanks for pointing out the bug. Yes as you may notice, this script is not fully tested.

As a replacement to this script, I think jlpkg is well maintained and works better than this one.

jlpkg --project=@ add $(cat requirements.txt) from fredrikekre/jlpkg#4

[mykelk]

Thanks! Shall I merge this PR in for now, and someone can add the jlpkg functionality in a later PR?

[johnnychen94]

Of course, you can merge it as you wish.