Remove service accounts cache (#685)

For optimization purposes operator was creating a cache map to remember
if service accounts and role binding was deployed to a namespace. This
could lead to a problem, when a namespace was deleted, since this
cache was not synchronized. For the sake of correctness remove the
cache, and check every time if required service account and rbac is
present. In the normal case this introduces an overhead of two API calls
per an event (one to get a service accounts, one to get a role binding),
which should not be a problem, unless proven otherwise.

pkg/controller/controller.go

@@ -58,7 +58,6 @@ type Controller struct {
 
 	PodServiceAccount            *v1.ServiceAccount
 	PodServiceAccountRoleBinding *rbacv1beta1.RoleBinding
-	namespacesWithDefinedRBAC    sync.Map
 }
 
 // NewController creates a new controller