Add zope.interface package

[IsakTheHacker]

Added the zope.interface package needed for zope. I have tested and built the package on all ABIs for Python 3.8

[mhsmith]

This package is now in the public repository for Python 3.8, 3.9 and 3.10. Thanks for the PR!

For future reference, zope itself still doesn't install, because of a different requirement, persistent:

      File "/Users/msmith/git/chaquo/chaquopy/server/pypi/pkgtest/app/build/generated/python/bp/setuptools/command/easy_install.py", line 1146, in run_setup
        raise DistutilsError("Setup script exited with %s" % (v.args[0],))
    distutils.errors.DistutilsError: Setup script exited with error: command 'Chaquopy_cannot_compile_native_code' failed with exit status 1
    ----------------------------------------
ERROR: Failed to install persistent>=4.1.0 from https://files.pythonhosted.org/packages/e7/bd/9efb67cf7704368663b7b07a99ad08e58fef69423fd90a35c7a75fa2b04c/persistent-5.1.tar.gz#sha256=97ccc2fa26cc9bdcc3be1fc65aa4f4f28afe5204c2d4fd24a67445908db7469b (from zope.container->zope).