Only add the django-oauth2-provider apps if the module is installed

otherwise log a warning

rest_framework/runtests/settings.py

@@ -98,9 +98,17 @@ INSTALLED_APPS = (
     'rest_framework',
     'rest_framework.authtoken',
     'rest_framework.tests',
+)
+
+try:
+    import provider
+    INSTALLED_APPS += (
         'provider',
         'provider.oauth2',
-)
+    )
+except ImportError, inst:
+    import logging
+    logging.warning("django-oauth2-provider is not install, some tests will be skipped")
 
 STATIC_URL = '/static/'