Upgrade Authorization::assertSatIsAllowed method

Only when the Identity owned a self-asserted token (SAT), or when the
identity does not have a tokey yet, allow the Identity to vet a self
asesrted token.

Author: MKodde

src/Surfnet/StepupMiddleware/ApiBundle/Tests/Authorization/Service/AuthorizationServiceTest.php

@@ -286,7 +286,6 @@ public function test_it_allows_when_identity_with_prior_sat_meets_all_requiremen
         $this->assertEmpty($messages);
     }
 
-
     public function test_recovery_tokens_never_owned_a_sat_token_but_did_own_other_token_type()
     {
         $identity = new Identity();