Environment details

• OS type and version:
• Python version: 3.8.5
• pip version: 20.0.2
• googleapis-common-protos version: 1.52.0

Steps to reproduce

1. the distributed sdist tarball (downloadable under https://files.pythonhosted.org/packages/source/g/googleapis-common-protos/googleapis-common-protos-1.52.0.tar.gz ) is missing the LICENSE file which is at the top of the directory

2. in order to include it, a MANIFEST.in needs to be added to the git repository that includes a reference to LICENSE (and potentially other files that should be part of the software distribution). see https://packaging.python.org/guides/using-manifest-in/#how-files-are-included-in-an-sdist