Added postgres service to the gitlab-ci.

.gitlab-ci.yml

@@ -13,9 +13,16 @@ run-tox-pipeline:
     - docker-executor
   image: python:3.10
 
+  services:
+    - postgres:latest
+
   # Change pip's cache directory to be inside the project directory since we can
   # only cache local items.
   variables:
+    POSTGRES_DB: postgres
+    POSTGRES_USER: nwa
+    POSTGRES_PASSWORD: nwa
+    DATABASE_URL: 'postgresql://nwa:nwa@postgres:5432/postgres'
     PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
 
   # Pip's cache doesn't store the python packages