ENYO-831: add dependency on async.js
ENYO-831: add dependency on async.js

- Async.js greatly simplifies the multiple steps of the OAuth
  dance.  Other multi-step operations may also benefit of this package,
  which is already a dependency of the server-side code.

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>

mcanthony/ares-project,enyojs/ares-project,enyojs/ares-project,mcanthony/ares-project,enyojs/ares-project,mcanthony/ares-project,mcanthony/ares-project,enyojs/ares-project,enyojs/ares-project,mcanthony/ares-project,mcanthony/ares-project