Bug 929895 - Blacklist some apps of notifications removal

Until bug 890440 is addressed, the system app clears all notifications
related to an application when it is launched/displayed. This is not
what we want for a couple of applications. We add a temporary hack to
blacklist those, thus avoiding to clear notifications.
Use npm mirror instead of npmjs.org
Bug 936639 - [Messages][Drafts] Create Drafts object + tests