Update sidekiq 3.0.2 -> 3.1.0

- New **remote control** feature: you can remotely trigger Sidekiq to
  quiet or terminate via API, without signals.  This is most useful on
  JRuby or Heroku which does not support the USR1 'quiet' signal.  Now
  you can run a rake task like this at the start of your deploy to quiet
  your set of Sidekiq processes.

```ruby
namespace :sidekiq do
  task :quiet => :environment do
    Sidekiq::ProcessSet.new.each(&:quiet!)
  end
end
```

- The Web UI can use the API to quiet or stop all processes via the Busy
  page.
- The Web UI understands and hides the `Sidekiq::Extensions::Delay*`
  classes, instead showing `Class.method` as the Job.
- Polish the Dashboard graphs a bit, update Rickshaw
- The poll interval is now configurable in the Web UI
- Delay extensions can be removed so they don't conflict with
  DelayedJob: put `Sidekiq.remove_delay!` in your initializer.
Update minitest 5.3.3 -> 5.3.4
Update aws-sdk 1.40.3 -> 1.41.0