Facebook email should be optional

As Twitter, the Facebook login (and maybe others?) should not rely only on it's email. 

Firs, the user can register with a mobile number and not email. 

Second, the user can not add the "email" scope to the facebook configuration and the user returned by the hybridauth will have both email and emailVerified empty.

Facebook does not allow the login through API without validating your email or mobile number anymore (did it allow it before?), so it's safe to assume that when the emailVerified is empty, either the user did not have one (mobile number login) or it's missing from the scope. No matter the case, i think it should be allowed to log in. 

If email is mandatory in someone's project, it should be added to the scope and checked the email presence after the authentication. For those projects where the user wants only to login with social providers, it should be enough.

Maybe, this could be done to other providers that rely on user's email.