Update dcmanager's mixins to use the base structure for API tests
and validate errors through pecan's abort method.
Test plan:
All of the tests were created taking into account the
output of 'tox -c tox.ini -e cover' command
Story: 2007082
Task: 49374
Change-Id: I28fb72a6767d80cdc04092d69afb572708039d8a
Signed-off-by: rlima <Raphael.Lima@windriver.com>
Wind River's Distributed Cloud system supports an edge computing
solution by providing central management and orchestration for a
geographically distributed network of Titanium Cloud systems.