Migrate to use aodh for alarm resources

Registered by huangtianhua

Ceilometer has moved all the alarming code and subsystem to the Aodh project:
https://review.openstack.org/#/c/196552
https://review.openstack.org/#/c/197161
Although now we can use ceilometerclient to redirect to aodh endpoint: https://review.openstack.org/#/c/202938 , but there are some reasons I believe we should to migrate to aodh:
1. ceilometer team plans to deprecate the reddirecting for aodh service maybe in two releases
2. aodh is the independent service

Blueprint information

Status:
Complete
Approver:
None
Priority:
Medium
Drafter:
huangtianhua
Direction:
Approved
Assignee:
huangtianhua
Definition:
Approved
Series goal:
None
Implementation:
Implemented
Milestone target:
milestone icon newton-2
Started by
huangtianhua
Completed by
huangtianhua

Related branches

Sprints

Whiteboard

Gerrit topic: https://review.openstack.org/#q,topic:bp/migrate-to-use-aodh-for-alarms,n,z

Addressed by: https://review.openstack.org/320207
    Migrate to use Aodhclient for alarm resources

Addressed by: https://review.openstack.org/325044
    Add aodh client plugin

Addressed by: https://review.openstack.org/326896
    Migrate to aodh for OS::Ceilometer::Alarm

Addressed by: https://review.openstack.org/334133
    WIP - Migrate to aodh for gnocchi alarms

Addressed by: https://review.openstack.org/334274
    Deprecate combination alarm

Addressed by: https://review.openstack.org/334280
    Change namespace 'ceilometer' to 'aodh'

(?)

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