* telemetry integration tests run in tempest-venv so plugin
needs to be installed in the same venv. devstack plugin installs
the plugin all-plugin venv so tests are not discovered by tempest.
In order to fix the same we need to use TEMPEST_PLUGINS vars for
the same.
* telemetry integration tests are dependent on heat-tempest-plugin
so we need to add that to the required projects.
Change-Id: Icab1e53d20bb7c95c232a4512e83905dcca7c599
ff913ae76b