Merge branch 'stable-3.0'

* stable-3.0:
  Update bazlets to latest stable-3.0
  Upgrade mockito-core to 2.28.2
  Don't import Id/Key/NameKey directly
  Bazel: Consume mockito library from plugin API

Upgrade bazlets to latest master.

Change-Id: I5f90f2be3f1c72b7766ac68febbe697b9fbf7703