support wheel build tag regexes

[graingert]

eg:

echo 'numpy==1.11.0' > requirements.txt
pip-compile --generate-hashes --expression="cpy35.*-macosx.*x86_64"

will include

• numpy-1.11.0-cp35-cp35m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl
• numpy-1.11.0.tar.gz

See peterbe/hashin#19 and #414

[jdufresne]

Since #414 has landed and been released, I don't think this feature is required any longer. That adds all hashes for all platforms. Is there still a use case not covered? I suggest we close.

[graingert]

Yeah I think this is not needed anymore

[jdufresne]

Thanks.