Merge branch 'stable-3.1' * stable-3.1: Documentation: Fix parentForDeletedProjects in config.md Adapt the change in Gerrit core Bump Bazel version to 2.2.0 Bump required Bazel version to 2.1.0 Upgrade bazlets to latest stable-2.16 to build with 2.16.16 API Documentation: Refactor to match other plugin documentation Add an empty tools/BUILD file explicitly for Bazel Upgrade bazlets to latest stable-2.16 Upgrade bazlets to latest stable-2.16 Upgrade bazlets to latest stable-2.15 Upgrade bazlets to latest stable-2.14 config.md: Correct formatting of config values Change-Id: Ib51ef5f829d0b318cffc41c44f83eb56e55a53df