Add Gistpen export functionality

* Gist method to create a new Gist from Gistpen
* Zip model now all returns with Gist ID information
  * Adapter and Query updated to match
* New App Facade for manipulating global objects
* Gistpens are exportable from settings page or WP-CLI
  * Add ajaxq to queue the export calls
* Mock out Controller\Sync & Account\Gist in Ajax with Mockery
  * Soon we can mock out everything with it
Uncomment option update
Switch to travis's new Docker containers

http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/