Use custom docker image with libvips installed in CI

.drone.yml

@@ -17,7 +17,7 @@ steps:
       branch:
         - master
   - name: rspec
-    image: guildeducation/rails:2.7.2-14.20.0
+    image: gitea.kosmos.org/kosmos/akkounts-ci:0.1.0
     environment:
       RAILS_ENV: test
       REDIS_URL: redis://redis:6379/0

ci/Dockerfile

@@ -0,0 +1,4 @@
+# syntax=docker/dockerfile:1
+FROM guildeducation/rails:2.7.2-14.20.0
+
+RUN apt-get update -qq && apt-get install -y --no-install-recommends ldap-utils libvips