sdist tarball (version 0.7.0) on pypi contains pre-compiled shared objects for python3.7

[toabctl]

Describe the bug

When downloading https://files.pythonhosted.org/packages/19/a7/c8b9c764ca4cf3ce7e5f773716575622b368430922cb054eef5b6a257476/aiokafka-0.7.0.tar.gz and then looking at the content:

$ tar tfz aiokafka-0.7.0.tar.gz |grep .so
aiokafka-0.7.0/aiokafka/record/_crecords/cutil.cpython-37m-x86_64-linux-gnu.so
aiokafka-0.7.0/aiokafka/record/_crecords/default_records.cpython-37m-x86_64-linux-gnu.so
aiokafka-0.7.0/aiokafka/record/_crecords/legacy_records.cpython-37m-x86_64-linux-gnu.so
aiokafka-0.7.0/aiokafka/record/_crecords/memory_records.cpython-37m-x86_64-linux-gnu.so

Theses files should not be included in a source tarball. This is a problem when trying to package the sdist tarball eg. for python3.8 . In that case, RPMs autodetection of requirements would still require python3.7:

[ods]

Autogenerated by cython .c files shouldn't be included too?

[asvetlov]

Many libraries (aiohttp included) are shipped with pre-generated .c files. It allows building tarball without cython installed. I don't know how is the requirement important though.

[toabctl]

.c files should be included. I'm talking about compiled share objects. Thanks for the fix!