Add user management scope

This splits the user and groups API into those who have just 'read' access
and those who have 'manage' access.

src/routes/groups.js

@@ -87,7 +87,7 @@ function updateMembers(req, res, next) {
 }
 
 function list(req, res, next) {
-    groups.getAllWithMembers(function (error, result) {
+    groups.getAll(function (error, result) {
         if (error) return next(new HttpError(500, error));
 
         next(new HttpSuccess(200, { groups: result }));