Move support plugins to their own folder.

lib/roles/device/plugins/identity.js

@@ -4,7 +4,7 @@ var devutil = require('../../../util/devutil')
 var logger = require('../../../util/logger')
 
 module.exports = syrup()
-  .dependency(require('./adb'))
+  .dependency(require('../support/adb'))
   .define(function(options, adb) {
     var log = logger.createLogger('device:plugins:identity')