Bug fix to authentication process on node

ccnode/ccnode.py

@@ -29,7 +29,16 @@ class CCNode(object):
         logging.debug('Authenticating user %s with password <%s>' % (login,
                       password))
         try:
-#TODO: authentify returns role
             role = self.server.authentify(login, password)
         except RpcError as err:
-            logging.warning('Authentication error')
+            if err.exception == 'AuthenticationError':
+                logging.warning('Authentication error')
+            else:
+                logging.warning('Unknown error while authenticating: %s' % err)
+            return False
+        else:
+            if role is not 'hypervisor':
+                logging.warning('Bad role affected by server: %s' % role)
+                return False
+            else:
+                return True