Install gcc in CI

.gitlab-ci.yml

@@ -6,7 +6,7 @@ py38-django31:
   stage: test
   image: python:3-alpine
   before_script:
-    - apk add postgresql-dev  # Add texlive
+    - apk add gcc postgresql-dev  # Add texlive
     - pip install tox --no-cache-dir
   script: tox -e py38-django31
 
@@ -14,7 +14,7 @@ linters:
   stage: quality-assurance
   image: python:3-alpine
   before_script:
-    - apk add postgresql-dev  # Add texlive
+    - apk add gcc postgresql-dev  # Add texlive
     - pip install tox --no-cache-dir
   script: tox -e linters