chore(pubsub): bump copyright year to 2020 (via synth)

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Commits in this repo since last synth:
01b7fb9 docs(bigquery): typo fix (#10209)
9ad21f4 feat(core): change default api_request() timeout to non-None (#10219)
8a0e129 fix(automl): fix TablesClient.predict for array and struct (#9991)
7e36fda deprecate(bigquery): deprecate client.dataset() in favor of DatasetReference (#7753)
73eac04 chore(recommender): release 0.2.0 (#10204)
c411e14 feat(recommender): add v1, set release level to beta (#10170)
8e7b7f8 feat(api_core): add retry param into PollingFuture() and it's inheritors (#9923)
0280a94 feat(bigquery): check rows argument type in insert_rows() (#10174)
3c4335d feat(bigquerydatatransfer): add service_account_name option to transfer configs (#10013)
a51da49 test(datacatalog): run unit tests with Python 3.8 (#10014)
c61c238 fix: be permssive about merging an empty struct (#10079)

Log from Synthtool

synthtool > Executing /tmpfs/src/git/autosynth/working_repo/pubsub/synth.py.
synthtool > Ensuring dependencies.
synthtool > Pulling artman image.
latest: Pulling from googleapis/artman
Digest: sha256:19e945954fc960a4bdfee6cb34695898ab21a8cf0bac063ee39b91f00a1faec8
Status: Image is up to date for googleapis/artman:latest
synthtool > Cloning googleapis.
synthtool > Running generator for google/pubsub/artman_pubsub.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/python/pubsub-v1.
synthtool > Copy: /home/kbuilder/.cache/synthtool/googleapis/google/pubsub/v1/pubsub.proto to /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/python/pubsub-v1/google/cloud/pubsub_v1/proto/pubsub.proto
synthtool > Placed proto files into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/python/pubsub-v1/google/cloud/pubsub_v1/proto.
synthtool > Replaced 'from google.cloud import pubsub_v1' in tests/unit/gapic/v1/test_publisher_client_v1.py.
synthtool > Replaced ' pubsub_v1' in tests/unit/gapic/v1/test_publisher_client_v1.py.
synthtool > Replaced 'from google.cloud import pubsub_v1' in tests/unit/gapic/v1/test_subscriber_client_v1.py.
synthtool > Replaced ' pubsub_v1' in tests/unit/gapic/v1/test_subscriber_client_v1.py.
synthtool > Replaced '# The name of the interface for this client. This is the key used to' in google/cloud/pubsub_v1/gapic/subscriber_client.py.
synthtool > Replaced '# The name of the interface for this client. This is the key used to' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced 'import google.api_core.gapic_v1.method\n' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced 'DESCRIPTOR = _MESSAGESTORAGEPOLICY,\n\\s+__module__.*\n\\s+,\n\\s+__doc__ = """' in google/cloud/pubsub_v1/proto/pubsub_pb2.py.
synthtool > No replacements made in google/cloud/pubsub_v1/gapic/subscriber_client.py for pattern subscription \(str\): The subscription whose backlog .*
(.*
)+?\s+Format is .*, maybe replacement is not longer needed?
synthtool > Replaced 'import functools\n' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced 'import pkg_resources\n' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced 'class PublisherClient' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced 'client_config \\(dict\\): DEPRECATED.' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced '# Raise deprecation warnings .*\n.*\n.*\n.*\n.*\n.*\n' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced '~google.api_core.page_iterator.PageIterator' in google/cloud/pubsub_v1/gapic/publisher_client.py.
synthtool > Replaced '~google.api_core.page_iterator.PageIterator' in google/cloud/pubsub_v1/gapic/subscriber_client.py.
synthtool > Replaced 'from google.iam.v1 import iam_policy_pb2' in google/cloud/pubsub_v1/gapic/transports/subscriber_grpc_transport.py.
synthtool > Replaced 'from google.iam.v1 import iam_policy_pb2' in google/cloud/pubsub_v1/gapic/transports/publisher_grpc_transport.py.
.coveragerc
.flake8
MANIFEST.in
docs/_static/custom.css
docs/_templates/layout.html
noxfile.py.j2
setup.cfg
Running session blacken
Creating virtual environment (virtualenv) using python3.6 in .nox/blacken
pip install black==19.3b0
black docs google tests noxfile.py setup.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/__init__.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/__init__.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/gapic/publisher_client_config.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/gapic/subscriber_client_config.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/gapic/transports/publisher_grpc_transport.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/gapic/transports/subscriber_grpc_transport.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/gapic/publisher_client.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/proto/pubsub_pb2_grpc.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/gapic/subscriber_client.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/tests/system/gapic/v1/test_system_publisher_v1.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/noxfile.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/tests/unit/gapic/v1/test_publisher_client_v1.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/tests/unit/gapic/v1/test_subscriber_client_v1.py
reformatted /tmpfs/src/git/autosynth/working_repo/pubsub/google/cloud/pubsub_v1/proto/pubsub_pb2.py
All done! ✨ 🍰 ✨
15 files reformatted, 49 files left unchanged.
Session blacken was successful.
synthtool > Wrote metadata to synth.metadata.

[busunkim96]

I didn't notice this when this change was being reviewed, but we'd have to make this change to the templates in gapic-generator to make this permanent. I don't anticipate us staying on the monolith(or supporting Python 2) past the first half of this year.

@plamut Would you be alright with letting this change be reverted? A synth replace is also an option if you feel it is important for Pub/Sub in particular.

Mostly trying to clear out synth PRs before repo split on Friday :)

[plamut]

@busunkim96 You mean reverting the change back to checking "if PY3"?

While this fix by an external contributor was welcome, it won't be applicable in the foreseeable future, as Python 4 has not been announced yet, and it's nearly certain that Python 2 support will be dropped way before that.

Feel free to do anything that makes the job on your part easier. :)

[plamut]

Looks good, I just have a question about a backslash.

The synth.metadata diff seems larger than usual (I might be wrong), but I assume that's correct. :)

[plamut]

What's the role of this backslash here? 😕
(could it be some kind of a leftover or a generator bug?)

[plamut]

Starting the repo split, please do not merge.

[busunkim96]

Closing, googleapis/python-pubsub#25 is the equivalent in the new repo.