First Pull request for code review - Registration, User Log in, Pagination

change the variable name po to more appropriate name
`$user = new User()`

also I noticed that you pass `$user_details` to User model and then call the `extract()` method.
you can instead do this po so you do not have pass the `$user_details` and extract it's values :smile:

`$user->set($user_details);`