Wheels do not specify Requires-Python metadata

[minrk]

PEP 345 defines Requires-Python for specifying the Python version, but it's not specified here.

That's not going to come up often for projects where conda-press is likely to be used, since the ABI tag is almost always more specific than the Python version. But in cases where there's an unbound pin (e.g. cp3 or py3), Requires-Python may be needed to enforce necessary lower limits.

[marcelotrevisani]

Hi @minrk ,
Indeed we should think about it, that might be a problem.

cc: @scopatz

[scopatz]

Thanks for bringing this up @minrk!

I think the could be easily shoved in the metadata. For noarch packages with no python version constraint, we can always shove in py>=2.7. A PR here would be awesome!