Replace using tests.utils part2

It is the second step to replace using tests.utils with
stack.common.test.
In this patch second part of tests is changed for using
openstack.common.test and added needed fixtures in test classes.

Change-Id: I81e3ff41827f7153b650255e219ce25cb282507b
bp: common-unit-tests
Merge "Replace using tests.utils part2"