feat: generate-circleci-config.py add resource_class

Author: simonsdave

CHANGELOG.md

@@ -8,7 +8,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
-* Nothing
+* added ```resource_class: medium``` to the CircleCI config
+  generated by ```generate-circleci-config.py```
 
 ### Changed
 

bin/generate-circleci-config.py

@@ -17,6 +17,7 @@
         auth:
           username: $DOCKER_EXECUTOR_DOCKERHUB_USERNAME
           password: $DOCKER_EXECUTOR_DOCKERHUB_PASSWORD
+    resource_class: medium
 
 commands:
   my_setup_remote_docker: