* remove ceilometer-api and ceilometer-collector service
* use ceilometer-notification to publish message to proper backend
* remove useless ceilometer_database_type and ceilometer_event_type
variables
* sync event_definitions.yaml, event_pipeline.yaml and pipeline.yaml
file with upstream
Change-Id: Ib39053cb5f70bd11ee61d3f26d5b28accecd7190