- Adding README, setup.py, MANIFEST.in, .coveragerc and tox.ini
- Adding google-cloud-pubsub as a dependency to the umbrella
  package
- Adding the pubsub subdirectory into the list of packages
  for verifying the docs
- Incorporating the pubsub subdirectory into the umbrella
  coverage report
- Adding the pubsub only tox tests to the Travis config
- Adding {toxinidir}/../core as a dependency for the pubsub
  tox config

Done via:

$ mkdir -p logging/google/cloud
$ cp google/__init__.py logging/google/__init__.py
$ git add logging/google/__init__.py
$ cp google/cloud/__init__.py logging/google/cloud/__init__.py
$ git add logging/google/cloud/__init__.py
$ git mv google/cloud/logging logging/google/cloud/logging
$ git mv unit_tests/logging logging/unit_tests

- Adding README, setup.py, MANIFEST.in, .coveragerc and tox.ini
- Adding google-cloud-logging as a dependency to the umbrella
  package
- Adding the logging subdirectory into the list of packages
  for verifying the docs
- Incorporating the logging subdirectory into the umbrella
  coverage report
- Adding the logging only tox tests to the Travis config
- Adding {toxinidir}/../core as a dependency for the logging
  tox config

In the process removing GRPC_PACKAGES entirely.