Python versions supported by packages aren't parsed properly.

[Ferroin]

Noticed initially with the yoctopuce package (which supports all versions of CPython in Gentoo, but can only be installed through gs-pypi with 2.7, 3.4, or 3.5).

Further confirmed with numerous other packages (in fact, almost anything in PyPI which has a supported version list that isn't exactly equal to what is being offered by all the gs-pypi packages in PYTHON_TARGETS).

It looks like #13 is a special case of this (packages which trigger that don't support any version of Python that Gentoo provides, and thus should not even have ebuilds offered).

May also be of interest for #17.