Users can now login with email address instead of username

[vince1995]

Edited UsersRouter so users can now also login with their email addresses

[acinader]

Hi @vince1995

Your pr is causing the tests to fail. You can check your code by running npm test

in this case the problem is that it is failing the lint check. npm run lint

[acinader]

this also looks like it is a duplicate of: #3612

[flovilmart]

@vince1995 closing as it doesn't fit what we'd expect for that feature, please refer to #3612 for more informations on how we'd like that feature to be integrated.