Merge branch 'stable-3.4'

* stable-3.4:
  Add Zuul postflight publish job
  docker: make sure to cleanup containers before force exit
  Harden shell commands
  Enable compiler warnings as errors
  Add bazel target for junit tests
  Add Zuul configuration to run tests on the CI node

Change-Id: Ice2cade040460ca6c86af8dab64d55e9bdf2f6fd