Add license validation to the config validation check

Should prevent a customer from accidentally saving a config that violates their license

Fixes https://jira.coreos.com/browse/QS-97

util/license.py

@@ -204,6 +204,10 @@ class EntitlementValidationResult(object):
       entitlement=repr(self.entitlement),
     ))
 
+  def description(self):
+    msg = '%s requires %s: has status %s'
+    return msg % (self.requirement.name, self.requirement.count, self.get_status())
+
   def as_dict(self, for_private=False):
     def req_view():
       return {