Docs: Add compatibility check badges to READMEs.

[ylil93]

Hello google package maintainers,
The badges being added to the READMEs in this PR will indicate each package's compatibility with other google packages. This addresses a set of user bugs which have happened when a user depends on two Cloud libraries (or runtimes that bundle libraries), say A and B, which both depend on library C. If the two libraries require different versions of C, the users can run into issues both when they pip install the libraries, and when they deploy their code. Our compatibility server checks that all libraries we make including these ones are self and pairwise compatible as well as not having any deprecated dependencies. The two badges being added to each README will mark the build for your project green when the latest version available on PyPI and github HEAD respectively meet all compatibility checks with itself and all other libraries. The badge target will link to a details page that elaborates on the current status. This should help you fix issues pre-release, to avoid user surprises. For more information, please take a look at our project charter at go/python-cloud-dependencies-project-charter and the badging PRD https://docs.google.com/document/d/1GYRFrfUou2ssY71AtnLkc8Sg1SD4dxqN4GzlatGHHyI/edit?ts=5c6f031d

[tseaver]

Logging failure due to a new flaky systest, reported in #8676.

Firestore failure due to existing flaky systest, #7130.

Storage failure due to a puzzling Kokoro issue (unable to import the stdlib's bz2 module).

Asset failure in the two VPCSC tests added in #8613 and updated in #8627.

[ylil93]

Logging failure due to a new flaky systest, reported in #8676.

Firestore failure due to existing flaky systest, #7130.

Storage failure due to a puzzling Kokoro issue (unable to import the stdlib's bz2 module).

Asset failure in the two VPCSC tests added in #8613 and updated in #8627.

I'm not sure what these mean... Could I have some clarification? From my point of view, this change only touches README files, so I don't see how it could be the cause of any of these breakages.

[tseaver]

@ylil93

I'm not sure what these mean... Could I have some clarification? From my point of view, this change only touches README files, so I don't see how it could be the cause of any of these breakages.

When reviewing a PR, we need to note the source of any CI failures, even those unrelated to the changes made by the PR.

[tseaver]

The CircleCI job actually completed successfully.

[tseaver]

@ylil93 Can you please explain the utility of the flags? For instance, on the asset/README.rst file I don't understand the errors for either the relesaed version or the master version.

[ylil93]

@ylil93 Can you please explain the utility of the flags? For instance, on the asset/README.rst file I don't understand the errors for either the relesaed version or the master version.

If you navigate to the badge target by clicking on it, you'll see an explanation for the incompatible status. Py2 errors will include a deprecation warning, but we do not trigger errors based on this warning, however it is included in the error description. Feel free to ignore them.

For PyPI, asset has an incompatibility with grpc-google-iam-v1 because google-cloud-asset 0.2.0 has requirement grpc-google-iam-v1<0.12dev,>=0.11.4, but you have grpc-google-iam-v1 0.12.3. This is true for both py2 and py3.

In other words, asset requires <0.12dev,>=0.11.4 of grpc-google-iam-v1, but during the build, 0.12.3 was used, which resulted in the incompatibility status. It looks like for the current release, asset had somehow pinned both 0.12.3 and the range <0.12dev,>=0.11.4.

For the github badge, the repo is incompatible with several other google packages for similar reasons.

The flags you should care about are:
self incompatible (red) - pip error when installing the given package
incompatible (red) - pip error when installed with another package
obsolete dependency (red) - refer to the high priority items in this
old dependency (yellow green) - refer to the low priority items in this