REF: use NoneOrPython from @sjagoe instead of hack for none key.
ENH: add more consistency checks in LegacySpecDepend.from_string.
STY: pep8-ify egg module.
FEAT: add python_tag entry in spec/depend.
MAINT: add missing module to git.
ENH: handle format '1.2' in parse_rawspec.
ENH: handle metadata_version 1.1 with unsupported python->python_tag.
STY: remove duplicate code.
ENH: more explicit exceptions for invalid egg metadata.
ENH: handle missing metadata in parse_rawspec.
REF: variables were a great invention, let's use them.
Merge pull request #24 from enthought/add_support_python_tag

Add support python tag