Remove admin auth when getting the list of Neutron API extensions.

Currently _refresh_neutron_extensions_cache() always authenticates
with Neutron using the configured Neutron admin credentials because
it doesn't have access to the calling context.  But it's actually
always called when a valid context exists, and the call to get the
list of extensions is not itself an admin operation.  By passing
the context down we can avoid this additional authentication step.

Change-Id: I9e7d9c5e424a6b39c8f8ee1c79f5fd8f48ad81a2
Closes-Bug: 1250850
Call get_pgsql_connection_info from _test_postgresql_opportunistically

The _test_postgresql_opportunistically method was calling the method to
parse the mysql connection URL which is wrong when there is one
specifically for postgresql, so call the right method.

This wasn't causing issues obviously but is something that needs to be
cleaned up regardless.

Closes-Bug: #1274718

Change-Id: Ic572e612c7ce31d854dc7258aa9c8b89a197260e
Prefix private methods with _ in docker driver

Private methods should be prefixed with a _ for
clarity. Although most private methods were
marked this way, a few were not.

Renames and marks private:
 is_daemon_running
 find_container_by_name
 get_available_resource

Closes-Bug: #1267664

Change-Id: Ifc6818b7620af972cc0eec6f9ef43610456895f1
Make baremetal driver use Flavor object instead of VirtAPI

This makes the baremetal driver use the Flavor object instead of
getting that information through the VirtAPI/conductor call.

Related to blueprint compute-manager-objects

Change-Id: I1cbc3fc77bbbcaa3c194f12814893c5937fb6e96
Adds unit test for etc/nova/policy.json data

* Test live etc/nova/policy.json data
* Convert all actions in policy.json to admin-only actions
* Check that Policy auth exception is raised when all above actions are
  called using non-admin context

Change-Id: I1b97987f8e9e3bacc606385a56daad189cf6ce19
Closes-Bug: #1262325
Merge "Call get_pgsql_connection_info from _test_postgresql_opportunistically"
Merge "Prefix private methods with _ in docker driver"
Merge "Remove admin auth when getting the list of Neutron API extensions."
Merge "Adds unit test for etc/nova/policy.json data"
Merge "Make baremetal driver use Flavor object instead of VirtAPI"