fix problems with migrations and start firebase migration

migrations/20150906_groups_remove_deleted_users.js

@@ -33,6 +33,7 @@ dbGroups.findEach({}, {_id: 1, members: 1}, {batchSize: 500}, function(err, grou
         countUsers++;
         console.log('User: ', countUsers);
 
+        // TODO updating the same group many times concurrently can cause problems?
         dbGroups.update({
           _id: group._id
         }, {

migrations/20150906_groups_remove_empty.js

@@ -1,5 +1,5 @@
 /*
- * Remove emoty groups
+ * Remove empty private groups
  */
 
 var mongo = require('mongoskin');
@@ -13,7 +13,11 @@ var dbGroups = db.collection('groups');
 console.log('Begins work on db');
 
 dbGroups.remove({
-  members: {$size: 0}
+  members: {$size: 0},
+  $or: [
+    {type: 'party'},
+    {privacy: 'private'}
+  ]
 }, function(err, res){
   if(err) throw err;