Use Bundler's retry option instead of our retry script

Signed-off-by: Rémy Coutable <remy@rymai.me>

.gitlab-ci.yml

@@ -22,7 +22,7 @@ before_script:
   - cp config/gitlab.yml.example config/gitlab.yml
   - touch log/application.log
   - touch log/test.log
-  - retry bundle install --without postgres production --jobs $(nproc) "${FLAGS[@]}"
+  - bundle install --without postgres production --jobs $(nproc) "${FLAGS[@]}" --retry 3
   - RAILS_ENV=test bundle exec rake db:drop db:create db:schema:load db:migrate
 stages: