fixed failing test on postgres

lib/migrator.js

@@ -35,6 +35,7 @@ module.exports = (function() {
     return new Utils.CustomEventEmitter(function(emitter) {
       if(options.method === 'down') {
         self.getCompletedMigrations(function(err, migrations){
+          migrations.reverse()
           self.processMigrations(err, migrations, options, emitter);
         });
       } else {
@@ -365,13 +366,15 @@ module.exports = (function() {
 
   var deleteUndoneMigration = Migrator.prototype.deleteUndoneMigration = function(from, to, callback) {
     var self = this;
-
     self.findOrCreateSequelizeMetaDAO().success(function(SequelizeMeta) {
-      SequelizeMeta
-        .find({ where: { from: from.migrationId.toString(), to: to.migrationId.toString() } })
-        .success(function(meta) {
-          meta.destroy().success(callback);
-        });
+      SequelizeMeta.find({ where: { from: from.migrationId.toString(), to: to.migrationId.toString() } })
+      .success(function(meta) {
+        if(meta){
+          meta.destroy().success(callback)
+        } else {
+          callback()
+        }
+      });
     });
   };