Presence: create an interface for backend operations
Presence: remove redis backend from main file
Presence: fix test creation process after interface refactoring
Presence: create a new backend file
Presence: fix example file
Presence: add err checking
Presence: remove unnecessary comment code block
Presence: fix comments
Presence: remove config setting from test file
Presence: refactor creating backend operation
Presence: create backed with NewRedis function
Merge pull request #1 from siesta/master.interface

Master.interface