Update Sidekiq from 4.2.1 to 4.2.7.
Includes various bug fixes, mostly for Rails 5.
Changelog: https://github.com/mperham/sidekiq/blob/fc168fe393bee3ad1fcbb52cff2d84af86c38cc4/Changes.md
cc: @rymai
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Includes various bug fixes, mostly for Rails 5.
Changelog: https://github.com/mperham/sidekiq/blob/fc168fe393bee3ad1fcbb52cff2d84af86c38cc4/Changes.md
cc: @rymai