Resource classes of managers should have methods like delete() and get()

The resource classes of managers should have methods like delete() and get(), perhaps some additional methods for specific classes. For example scenario tests use basic methods delete and get, while doing cleanup.

Traceback (most recent call last):
  File "/opt/stack/tempest/tempest/scenario/test_threshold_alarm.py", line 42, in cleanup_wrapper
    self.cleanup_resource(resource, self.__class__.__name__)
  File "/opt/stack/tempest/tempest/scenario/manager.py", line 117, in cleanup_resource
    resource.delete()
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/alarms.py", line 52, in __getattr__
    return super(Alarm, self).__getattr__(k)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/openstack/common/apiclient/base.py", line 460, in __getattr__
    self.get()
  File "/opt/stack/python-ceilometerclient/ceilometerclient/openstack/common/apiclient/base.py", line 473, in get
    new = self.manager.get(self.id)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/alarms.py", line 52, in __getattr__
    return super(Alarm, self).__getattr__(k)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/openstack/common/apiclient/base.py", line 463, in __getattr__
    raise AttributeError(k)
AttributeError: id