Move v3 identity endpoint group tests to work w/ pre-prov

I don't see any limitations by using pre-provisioned
credentials for these tests:

* test_create_list_show_check_delete_endpoint_group
* test_update_endpoint_group

Note that these tests aren't interop tests [0] so can
be safely moved.

[0] http://codesearch.openstack.org/?q=admin.v3.test_endpoint_groups&i=nope&files=&repos=interop

Change-Id: I2638348989ecdda14a88b0f8817ff42a1a6c9e77
1 file changed