ci: install bundler < version 2

.gitlab-ci.yml

@@ -41,7 +41,7 @@ before_script:
   - curl -s couchdb:5984
   - cp config/ci/gitlab/couchdb.yml config/couchdb.admin.yml
   - cp config/ci/gitlab/couchdb.yml config
-  - gem install bundler  --no-ri --no-rdoc
+  - gem install bundler  --version '< 2'
   - bundle install -j $(nproc) --path vendor --without development debug
   - bundle exec rake RAILS_ENV=test db:rotate
   - bundle exec rake RAILS_ENV=test db:migrate