feat(rm): switched to promises

BREAKING CHANGE: Switches to a Promise-based API and removes callback stuff

Author: zkat

lib/content/rm.js

@@ -1,9 +1,11 @@
 'use strict'
 
+var Promise = require('bluebird')
+
 var contentPath = require('./path')
-var rimraf = require('rimraf')
+var rimraf = Promise.promisify(require('rimraf'))
 
 module.exports = rm
-function rm (cache, address, cb) {
-  rimraf(contentPath(cache, address), cb)
+function rm (cache, address) {
+  return rimraf(contentPath(cache, address))
 }