Merge the tip of origin/release/proposed/2019.2.0 into origin/release/2019.2.0

7f244edf Update docker image
6d66bf5f Rework git tag mechanism
ca5f0838 Update alerta receiver for alertmanager with basic http auth
03fcf4cc Update docker image for sanity tests PROD-36949
38cc22a0 Fix misprint in ceph-delete-node job

Change-Id: I41fc3d6a717885c775852e2d894c160334ffcae3