yarn install on CI

.gitlab-ci.yml

@@ -8,6 +8,7 @@ test:
   script:
     - cd schedules
     - bundle install
+    - yarn install
     - rails db:migrate
     - rails test
     - rubocop

schedules/Dockerfile

@@ -9,6 +9,7 @@ EXPOSE 3000
 ENV RAILS_ENV production
 
 RUN bundle install
+RUN yarn install
 RUN export SECRET_KEY_BASE=$(rails secret)
 RUN rails assets:precompile
 RUN rails db:migrate