⚡️(circleci) use base python docker img to push pkgs

Similarily to previous improvement, publishing a package to PyPI only
requires twine and configured environment variables. Let's make things
faster and simpler for such a simple task.

.circleci/config.yml

@@ -454,37 +454,23 @@ jobs:
   #   * you have define both the TWINE_USERNAME & TWINE_PASSWORD secret
   #     environment variables in CircleCI UI (with your PyPI credentials)
   pypi:
-    machine: true
+    docker:
+      - image: circleci/python:3.7-stretch
     working_directory: ~/fun
     steps:
       - checkout
-      - restore_cache:
-          keys:
-            - docker-debian-images-ci-{{ .Revision }}
-      - run:
-          name: Load images to docker engine
-          command: |
-            docker load < docker/images/dev/richie.tar
       # Restore built python packages
       - attach_workspace:
           at: ~/fun
       - run:
           name: List built packages
           command: ls dist/*
+      - run:
+          name: Install base requirements (twine)
+          command: pip install .[ci]
       - run:
           name: Upload built packages to PyPI
-          command: |
-            docker-compose \
-              -p richie-ci \
-              -f docker/compose/ci/postgresql/docker-compose.yml \
-              --project-directory . \
-              run --rm --no-deps \
-                --user="$(id -u)" \
-                --volume="$PWD:/app" \
-                -e TWINE_USERNAME \
-                -e TWINE_PASSWORD \
-                app \
-                twine upload dist/*
+          command: twine upload dist/*
 
   # ---- DockerHub publication job ----
   hub:

setup.cfg

@@ -56,6 +56,7 @@ dev =
     pytest-cov==2.6.1
     pytest-django==3.4.8
     responses==0.10.6
+ci =
     twine==1.13.0
 sandbox =
     django-configurations==2.1