This reverts the workaround for the devstack plugin,
as now the gate jobs pass(with the plugin and no devstack
tree heat code) and make it only a devstack plugin.
Remove the redundant code for bulding a pip mirror
for heat agents. At present it's used by
test_server_software_config.py, which is disabled.
We may use RDO packages for the agents in the future,
when we plan to enable these tests.
When heat is enabled, both stack.sh and plugin try to do account
creation (as part of keystone startup which fails as heat is not yet
installed), intialize the db and start the services. In this patch
(which is a workaround), we'll use a set of dummy function calls to
avoid it. We'll remove these functions later(once we clean up devstack
stack.sh) and rename the currently used functions.
This adds the actual devstack plugin, devstack should not run the heat code
in the devstack project.
Note that this is not yet configured to run in the gate.