👷 update push cmd heroku

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/python:3.8.5
+      - image: circleci/python:3.9-buster-node-browsers
     steps:
       - checkout
       - restore_cache:
@@ -19,7 +19,7 @@ jobs:
             - venv
   test:
     docker: 
-      - image: circleci/python:3.8.5
+      - image: circleci/python:3.9-buster-node-browsers
         environment:
           DATABASE_URL: postgresql://myUsr:somePwd@localhost:5432/dbtest
           FLASK_APP: /home/circleci/repo/autoapp.py
@@ -33,7 +33,7 @@ jobs:
     steps:
       - checkout
       - restore_cache:
-          key: deps-{{ checksum "requirements/dev.txt"}}-{{ .Environment.CACHE_VERSION }}
+          key: dependencies-{{ checksum "requirements/dev.txt"}}-{{ checksum "requirements/prod.txt" }}
       - run: docker container run --name flask_db_test -e POSTGRES_PASSWORD=somePwd -e POSTGRES_USER=myUsr -p 5432:5432 -d dbtest
       - run: 
           name: sleep 1 
@@ -52,11 +52,12 @@ jobs:
       - image : buildpack-deps:trusty
     steps:
       - checkout
+    staging:
+      - branch: main
       - run:
           name: Heroku deploy
           command: |
-            git config --global push.default matching
-            git push https://heroku:$HEROKU_API_KEY@git.heroku.com/$HEROKU_APP_NAME.git HEAD:main
+            git push https://heroku:$HEROKU_API_KEY@git.heroku.com/$HEROKU_APP_NAME.git 
       - run:
           name: Smoke test
           command: |