moving codecov bash executor to the repository

relying on the contents of the github repo directly

Author: chayim

.circleci/config.yml

@@ -27,7 +27,7 @@ jobs:
       - checkout
       - run: make test
       - early_return_for_forked_pull_requests
-      - run: bash <(curl -s https://codecov.io/bash) -t ${CODECOV_TOKEN}
+      - run: bash <(curl -s https://raw.githubusercontent.com/codecov/codecov-action/master/codecov) -t ${CODECOV_TOKEN}
 
 workflows:
   version: 2