Revert "try bigger runner"

circleci app showed I could opt for a bigger runner but in fact I can
only get medium.

This reverts commit 7ebb023.

Author: elelay

.circleci/config.yml

@@ -14,7 +14,6 @@ jobs:
       - run: rm -Rf _build/pythonbase.app/ _build/run-*
       - store_artifacts:
           path: /Users/distiller/project/_build
-    resource_class: large
 
 workflows:
   version: 2