Remove user bio feature (#1214)

The feature is very limited in scope, and we hope for community
extensions to take over this feature and make it much better.

js/lib/models/User.js

@@ -16,8 +16,6 @@ Object.assign(User.prototype, {
   password: Model.attribute('password'),
 
   avatarUrl: Model.attribute('avatarUrl'),
-  bio: Model.attribute('bio'),
-  bioHtml: computed('bio', bio => bio ? '<p>' + $('<div/>').text(bio).html().replace(/\n/g, '<br>').autoLink({rel: 'nofollow'}) + '</p>' : ''),
   preferences: Model.attribute('preferences'),
   groups: Model.hasMany('groups'),