Use poetry for dependency management

.gitlab-ci.yml

@@ -34,13 +34,13 @@ python tests:
     key: "$CI_JOB_NAME-$CI_COMMIT_REF_SLUG"
     paths:
       - .cache/pip
-      - env/
+      - .venv/
   before_script:
-    - python3 -m venv env
-    - source env/bin/activate
-    - pip install -r requirements/gitlab.txt
+    - pip install poetry
+    - poetry config virtualenvs.in-project true
+    - poetry install --no-interaction
   script:
-    - python src/manage.py test newsreader
+    - poetry run src/manage.py test newsreader
 
 javascript tests:
   image: node:12
@@ -76,15 +76,15 @@ python linting:
     key: "$CI_JOB_NAME-$CI_COMMIT_REF_SLUG"
     paths:
       - .cache/pip
-      - env/
+      - .venv/
   before_script:
-    - python3 -m venv env
-    - source env/bin/activate
-    - pip install -r requirements/gitlab.txt
+    - pip install poetry
+    - poetry config virtualenvs.in-project true
+    - poetry install --no-interaction
   script:
-    - isort src/ --check-only --recursive
-    - black src/ --line-length 88 --check
-    - autoflake src/ --check --recursive --remove-all-unused-imports --ignore-init-module-imports
+    - poetry run isort src/ --check-only --recursive
+    - poetry run black src/ --line-length 88 --check
+    - poetry run autoflake src/ --check --recursive --remove-all-unused-imports --ignore-init-module-imports
 
 deploy:
   stage: deploy