credentials validation (#194)

Co-authored-by: Michael Hoennig <michael@hoennig.de>
Reviewed-on: https://dev.hostsharing.net/hostsharing/hs.hsadmin.ng/pulls/194
Reviewed-by: Marc Sandlus <marc.sandlus@hostsharing.net>

src/main/resources/api-definition/accounts/credentials-with-uuid-used.yaml

@@ -4,7 +4,6 @@ post:
     description: 'Is called when credentials got used for a login.'
     operationId: credentialsUsed
     parameters:
-        -   $ref: 'auth.yaml#/components/parameters/assumedRoles'
         -   name: credentialsUuid
             in: path
             required: true