Fix torpid coordinator unit tests
Fix torpid coordinator unit tests

The test_coordination.py unit module tests a _reconnect() method
which does a randomly seeded exponential retry backoff.  This
retry/backoff mechanism introduces needless delay in unit test
runs.

This commit mocks out random.uniform, improving run time by about
a factor of nine, as documented in the accompanying bug.

Closes-Bug: #1536750

Change-Id: I83fafba17be99cbe972dfb60fe87dac6dc3756cf

NetApp/cinder,bswartz/cinder,mahak/cinder,cloudbase/cinder,mahak/cinder,openstack/cinder,Datera/cinder,ge0rgi/cinder,bswartz/cinder,Hybrid-Cloud/cinder,cloudbase/cinder,j-griffith/cinder,dims/cinder,Nexenta/cinder,Hybrid-Cloud/cinder,NetApp/cinder,eharney/cinder,dims/cinder,Nexenta/cinder,phenoxim/cinder,openstack/cinder,j-griffith/cinder,eharney/cinder,phenoxim/cinder,Datera/cinder