Install base requirements in GitLab CI

.gitlab-ci.yml

@@ -25,6 +25,7 @@ pytest:
   stage: test
   before_script:
     - pip install -U pip setuptools
+    - pip install -r requirements/base.txt
     - pip install -r requirements/test.txt
     - apt-get update && cat system-requirements-debian.txt | xargs apt-get install -y
     - python manage.py collectstatic