OAuth2.0 Provider - Bugfixes

• #753: Fix acceptance of valid IPv6 addresses in URI validation

OAuth2.0 Client - Bugfixes

• #730: Base OAuth2 Client now has a consistent way of managing the scope: it consistently
  relies on the scope provided in the constructor if any, except if overridden temporarily
  in a method call. Note that in particular providing a non-None scope in
  prepare_authorization_request or prepare_refresh_token does not override anymore
  self.scope forever, it is just used temporarily.
• #726: MobileApplicationClient.prepare_request_uri and MobileApplicationClient.parse_request_uri_response,
  ServiceApplicationClient.prepare_request_body,
  and WebApplicationClient.prepare_request_uri now correctly use the default scope provided in
  constructor.
• #725: LegacyApplicationClient.prepare_request_body now correctly uses the default scope provided in constructor

OAuth2.0 Provider - Bugfixes

• #711: client_credentials grant: fix log message
• #746: OpenID Connect Hybrid - fix nonce not passed to add_id_token
• #756: Different prompt values are now handled according to spec (e.g. prompt=none)
• #759: OpenID Connect - fix Authorization: Basic parsing

General

• #716: improved skeleton validator for public vs private client
• #720: replace mock library with standard unittest.mock
• #727: build isort integration
• #734: python2 code removal
• #735, #750: add python3.8 support
• #749: bump minimum versions of pyjwt and cryptography