👷 update python version

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/python:3.9-buster-node-browsers
+      - image: circleci/python:3.8
     working_directory: ~/repo
     steps:
       - checkout
@@ -25,7 +25,7 @@ jobs:
           
   test:
     docker: 
-      - image: circleci/python:3.9-buster-node-browsers
+      - image: circleci/python:3.8
       - image: circleci/postgres:9.6.2-alpine
         environment:
           POSTGRES_USER: postgres
@@ -37,7 +37,6 @@ jobs:
       - restore_cache:
           keys: 
             -dependencies-{{ checksum "requirements/dev.txt"}}-{{ checksum "requirements/prod.txt" }}
-            -dependencies
       - run:
           name: db upgrade 
           command: |