Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  Forwarder tests: Replace null event json with valid one
  Add .apt_generated directory to .gitignore
  Update mockito-core to 2.24.0
  RestForwarderServletModuleIT: Add a cache wildcard endpoint test
  RestForwarderServletModule: Add missing wildcard to event endpoint

Change-Id: I58e9a3f87850d78405f53d052cfeb6cce3cba196