Key error when auth in standalone mode

Fix a key error caused from the response of authing
in stand alone mode. The keystone docs indicate that
the schema for a response user name is ['user']['name']
rather than ['user']['username'].

Change-Id: I9ac94feeef8f9f2dedaa3842f64a3491e701e199

heat/common/auth_password.py

@@ -74,7 +74,7 @@ class KeystonePasswordAuthProtocol(object):
         tenant_id = token_info['token']['tenant']['id']
         tenant_name = token_info['token']['tenant']['name']
         user_id = token_info['user']['id']
-        user_name = token_info['user']['username']
+        user_name = token_info['user']['name']
         roles = ','.join(
             [role['name'] for role in token_info['user']['roles']])
         service_catalog = token_info['serviceCatalog']

heat/tests/test_auth_password.py

@@ -45,7 +45,7 @@ TOKEN_RESPONSE = {
     },
     'user': {
         'id': 'user_id1',
-        'username': 'user_name1',
+        'name': 'user_name1',
         'roles': [
             {'name': 'role1'},
             {'name': 'role2'},