Revert Dockerfile to use latest version of image

As it is built locally within one step and never pulled between steps,
this should not be a problem

docker/development/Dockerfile

@@ -1,5 +1,5 @@
 # Build production container locally first with following tag
-FROM turniere-backend/production:local
+FROM registry.gitlab.com/turniere/turniere-backend/production
 WORKDIR /app
 RUN bundle install --deployment --with development
 ENV RAILS_ENV development

docker/test/Dockerfile

@@ -1,5 +1,5 @@
 # Build development container locally first with following tag
-FROM turniere-backend/development:local
+FROM registry.gitlab.com/turniere/turniere-backend/development
 WORKDIR /app
 RUN bundle install --deployment --with test
 ENV RAILS_ENV test