Ensure the user monkey patching is done for the API tests

When running a subset of the tests, the get_user middleware monkey
patching in openstack_auth.utils did not always happen, causing some
of the tests to fail due to missing expected properties.

Fixes bug #1209177

Change-Id: Ic00b842e740954b0f36353381f511f7ba3eab70b
Merge "Ensure the user monkey patching is done for the API tests"