Telemetry does not support mongodb anymore and hence mongodb
was dropped from tripleo. Lets drop this code completely so
we dont end up maintaining dead code.
- drop mongodb support
- change default ceilometer publishers to gnocchi and panko
- add release note for dropping support of mongodb
Change-Id: I79bbc6be20bf538173b48976401a43d417520481
(cherry picked from commit d90c4b1b68)
ab1ac2888e