Add functional tests for Manila consistency groups

This commit adds tempest functional tests for Manila consistency
groups and cgsnapshot objects and actions. By default these tests are
enabled; 3rd party CI systems should disabled these tests through the
RUN_MANILA_CG_TESTS environment variable if their driver does not
support consistency groups.

Partially implements bp manila-consistency-groups
Change-Id: I3297e02ad53c328f0bfe5245fefdb6af80552b4a
10 files changed
tree: ebf36992fadd4af4a6d75c5b7925a018c3cd18a4
  1. manila_tempest_tests/