docs(DEVELOPMENT) Fix doc docker call

DEVELOPING.md

@@ -19,7 +19,7 @@ If you want to see debug logs, set `DEBUG` to `True` in `settings.py`.
 Once the above compose file is running, you can use the `mock_web_app`
 container to run the tests against the `doctor` container:
 
-    docker exec -it mock_web_app_doctor python3 -m unittest doctor.tests
+    docker exec -it mock_web_app python3 -m unittest doctor.tests
 
 
 ## Building Images