Sidekiq is properly restarted after a crash when deploying with Capsitrano2

Currently, if sidekiq is not running but the pid file exists, then it won't be properly started when deploying with Capistrano2.

Here is why:
 - The stop method does not run sidekiqctl if the process is not running
 - The start method does not run sidekiqctl is a pid file already exists

The end result is sidekiq not running after a deploy. My fix is to clean up the pid file even sidekiq is not running.