add postgres service

.gitlab-ci.yml

 image: docker:latest
 
+variables:
+  POSTGRES_HOST: "db-local"
+  POSTGRES_DBNAME: "postgres"
+  POSTGRES_USER: "postgres"
+  POSTGRES_PASSWORD: "test"
+
 stages:
   - test
 
 test-style:
   stage: test
-  needs: []
+  image: python:3.9
   script:
     - pip install -q -r requirements-test.txt
     - black ./autocomplete_multi_models/ --check --diff --config ./pyproject.toml
@@ -13,6 +19,9 @@ test-style:
 test:
   stage: test
   image: python:3.9
+  services:
+    - name: postgres:14
+      alias: "db-local"
   script:
-    - pip3 install -r requirements.txt -r requirements-test.txt
+    - pip install -r requirements.txt -r requirements-test.txt
     - coverage report --skip-covered --omit=*/wsgi.py,*/asgi.py,manage.py,*/apps.py,setup.py