Add SuckerPunch backend support
Add more tests
Fix comments for connection pooling
Fix SuckerPunch tests
Remove temporary patch to fix sucker_punch/testing/inline
Remove override to #mailer_class

- Thank @orendon
add "que" development dependency
add Que backend support
add que backend test to worker_test
add information about Que backend to readme
Merge pull request #47 from kmayer/sucker-punch

Add SuckerPunch backend support
manually merge of #57
Merge branch 'marshall-lee-que_support'

* marshall-lee-que_support:
  add information about Que backend to readme
  add que backend test to worker_test
  add Que backend support
  add "que" development dependency