add keystone group tests

add two testcases for group and group users:
test_group_create_update_get
test_group_users_add_list_delete

Change-Id: I9fa1821e219c54715f821999dac100daa68283f0
Remove vim headers

We don't need to have the vim headers in each source files. We can set
it in our vimrc file instead. Also if set incorrectly, gate (pep8 check)
will catch the mistakes.

More discussions:
http://lists.openstack.org/pipermail/openstack-dev/2013-October/017353.html

Change-Id: I43703e2289212389c7841f44691ae7849ed1f505
Closes-Bug: #1229324
Merge "Remove vim headers"
Merge "add keystone group tests"