This permits users to easily customize where the ip address
should be resolved. When fronting the application with a webserver or
load balancer, the ip address may be the server and not be the user.
E.g. consider the IP address is passed as the header: "X-Forwarded-For".
```ruby
class User
devise :trackable
protected
def extract_ip_from(request)
request.headers["X-Forwarded-For"]
end
end
```
* Fix missing validations on Signup
This commit fixes issue
https://github.com/plataformatec/devise/issues/4673
This removes `validate: false` from saving a record when `Trackable` is
in use.
* Add test case
* Add mongoid model
