Deploy app into device using node-firefoxos-cli (remastered to use promises).

This will add a new task 'deploy' that will install the app in the phone and launch it.

Uses https://www.npmjs.com/package/node-firefoxos-cli that is a bit old but so far is working.
I noticed a weird behavior, cause of the promise nature of that library, on gulp the task finish but the process doesnt when executing:
`gulp deploy`

Fix #7
nit: this should use DIST_ROOT constant.