Start on Capistrano 3 compatibility
Extract task
Use capistrano 3 syntax for task definition
Maintain backwards-compat with capistrano 2
Merge branch 'blackxored/capistrano3'
Allow supplying API key in deploy.rb

This allows including your Bugsnag API key in your Capistrano deploy.rb file:

set :bugsnag_api_key, "abcdef1234567890"