Merge branch 'master' into populator

.gitlab-ci.yml

Gemfile

Gemfile.lock

app/builders/learning_object/draft_builder.rb

app/builders/learning_object_builder.rb

app/controllers/concerns/paginator.rb

app/controllers/v1/collections_controller.rb

app/controllers/v1/complaints_controller.rb

app/controllers/v1/educational_stages_controller.rb

app/controllers/v1/feed_controller.rb

app/controllers/v1/learning_objects/attachment_controller.rb

app/controllers/v1/learning_objects/chunks_controller.rb

app/controllers/v1/learning_objects/publishes_controller.rb

app/controllers/v1/learning_objects/uploads_controller.rb

app/controllers/v1/learning_objects_controller.rb

app/controllers/v1/reviews_controller.rb

app/controllers/v1/search_controller.rb

app/controllers/v1/subjects_controller.rb

app/models/collection.rb

app/models/complaint.rb