Drop the group/person/role global fixtures, the fixture loader in

Django 1.6 refuses to load them because they have dangling foreign
keys, and in rewriting them it turns out it is easier to do so in code
- so refactor the test data generation code to have a separate
function with the unchanging base data and call that from the global
fixture setup
 - Legacy-Id: 6917

Author: OleLaursen

ietf/group/fixtures/groups.json

@@ -220,7 +220,7 @@
 TEST_RUNNER = 'ietf.utils.test_runner.IetfTestRunner'
 
 # Fixtures which will be loaded before testing starts
-GLOBAL_TEST_FIXTURES = [ 'names','groups','persons', 'roles']
+GLOBAL_TEST_FIXTURES = [ 'names','ietf.utils.test_data.make_immutable_base_data' ]
 
 TEST_DIFF_FAILURE_DIR = "/tmp/test/failure/"