AS-334: Auth token delay

Having a delay before returning a fresh authentication token. This *could* reduce 401 errors since one of the possible reasons mentioned by Identity team was replication. 
+1!!  I think it's great to split this out to test, although maybe a slightly more integration-y test that makes sure of the effect of the composition would also be useful?  To test that there is no waiting if the the value is cached, etc.  

I know all of this follows logically from composition order, but maybe an end-to-end auth tests could catch future unintended consequences too, if some other authenticator needed to be inserted.