Update README.md testing section (#2748)

Issue #440 has been resolved, so this line can be removed?

Author: Adan Amarillas

README.md

@@ -58,7 +58,7 @@ Please read and abide by our [Code of Conduct](https://publiclab.org/conduct); o
 7. Install static assets (like external javascript libraries, fonts) with `bower install`
 8. Start rails with `passenger start` from the Rails root and open http://localhost:3000 in a web browser.
 9. Wheeeee! You're up and running! Log in with test usernames "user", "moderator", or "admin", and password "password".
-10. Run `rake test` to confirm that your install is working properly. For some setups, you may see warnings even if test pass; [see this issue](https://github.com/publiclab/plots2/issues/440) we're working to resolve.
+10. Run `rake test` to confirm that your install is working properly.
 
 ## How to start and modify cron jobs