[qa] Updated qa.py openwisp#20

Fixes openwisp#20

openwisp_utils/qa.py

@@ -34,7 +34,7 @@ def check_migration_name():
     """
     args = _parse_args()
     if not args.migration_path:
-        raise Exception("CLI arguement `migration-path` is required "
+        raise Exception("CLI argument `migration-path` is required "
                         "but not found")
     if args.migrations_to_ignore is None:
         args.migrations_to_ignore = 0