Turn of cache dir to save memory.

.drone.yml

@@ -3,13 +3,14 @@ name: default
 
 steps:
   - name: tests
-    image: python:3.6
+    image: python:3.6-alpine
     environment:
       PYTHONUSERBASE: /drone/src/cache/packages
       POSTGRES_USER: mhackspace
       USE_DOCKER: yes
       DJANGO_SETTINGS_MODULE: config.settings.test
     commands:
+      - apk add git build-base gcc python3-dev postgresql-dev musl-dev jpeg-dev zlib-dev openjpeg-dev tiff-dev libffi-dev freetype-dev libev-dev lcms2-dev tk-dev tcl-dev harfbuzz-dev fribidi-dev libxslt-dev
       - cp -n env.example .env
       - mkdir -p ./cache/packages ./cache/pip
       - pip install --user --cache-dir ./cache/pip -r ./requirements/test.txt