Fix compat datetime import when oauth2 provide does not support timezone aware datetimes

.gitignore

@@ -4,6 +4,7 @@
 .*
 
 html/
+htmlcov/
 coverage/
 build/
 dist/

rest_framework/compat.py

@@ -494,7 +494,8 @@ try:
     if provider_version in ('0.2.3', '0.2.4'):
         # 0.2.3 and 0.2.4 are supported version that do not support
         # timezone aware datetimes
-        from datetime.datetime import now as provider_now
+        import datetime
+        provider_now = datetime.datetime.now
     else:
         # Any other supported version does use timezone aware datetimes
         from django.utils.timezone import now as provider_now