Sanic-security

+ Previous client session is deactivated when a new one is requested (for example when requesting captcha).
+ Two-factor authentication fix and error message clarification.
+ Documentation revision.

+ Login credentials are received via authorization header.
+ Tests revised accordingly to use authorization header.
+ Major documentation revisions.
+ `MAX_ATTEMPTS_ALLOWED` configuration field added.
+ `CredentialsError` exception implemented for an invalid login.
+ `JWTDecodeError` exception implemented if an error occurs during session JWT decoding.
+ `ChallengeError` exception implemented if a verification session challenge attempt is incorrect.
+ `crosscheck_code` method renamed to `check_code`

+ `validate_location` renamed to `check_client_location`.
+ `UnrecognisedLocationError` now raised instead of `SessionError` when checking client location.

+ Improved refresh token reuse protection.
+ `crosscheck_location` renamed to `validate_location`.
+ Sessions marked as deleted won't be taken into consideration during location validation.

+ Authorization revamp. `Permission` object removed as permissions are stored in a `Role` object. An account's roles can be accessed via the `roles` variable value via a many-to-many relationship.
+ Session access/refresh token's.
+ Model revisions.
+ Improved registration error handling.
+ Password character limit check during registration.
+ Uid removed.
+ Test improvements.
+ Documentation revisions.

+ Setup.py optional development dependencies.