Load app before loading legacy client in tests.

When you load an old version of keystoneclient doing legacy tests and
then start the test app the ec2 work that depends on keystoneclient sees
the recently loaded legacy one which doesn't have the required modules
in it.

If we load the app first the ec2 modules are resolved and finds the
original keystone client. The ec2 module then uses
'from keystoneclient.contrib.ec2 import utils as ec2_utils' so the
ec2_utils reference is kept in the file scope so isn't affected by the
tests changing keystoneclient.

It is not a long term fix for bug 1178532 but it solves the immediate
symptoms when running client tests independently.

Change-Id: I7267ca0d4740f037884fae95f8a6562ee86584b9
Merge "Load app before loading legacy client in tests."