Consider removing namespace_packages argument from setup.py

[calder]

The namespace_packages argument to setup prevents google/__init__.py from being included in the Pip package, which in turn prevents Bazel rules_python from treating google as a namespace package. This makes it incompatible with the protobuf package (and any other google-rooted packages) when used under Bazel.

bazelbuild/rules_python#93 tracks adding support for namespace_packages in rules_python.

[theacodes]

Sorry, we can't do that. There are roughly 40 packages that live under the google namespace. All of them must cooperate for this to work. Bazel needs to be fixed to support namespace packages.