Cleanup imports in code

In some part in the code we import objects. In the Openstack
style guidelines they recommend to import only modules[1].

[1]: http://docs.openstack.org/developer/hacking/#imports

Change-Id: I66fd1847c529ae73b6d5961cdf3daa460c50020d
1 file changed
tree: 6238e4a400b4bea5392ab016dad7347d07a432e2
  1. ceilometer/