Using Resources to store data in json file in Angular

Folks I have a form on my website who's data I want to store in a json file.

Here is the code for the form:

 <form>
    <input ng-model="obj.firstname">
    <input ng-model="obj.lastname">     
    <button ng-click="storedata()">Click here to store data</button>        
</form>

My Angular code is as below:

var myApp = angular.module('app', ['ui.bootstrap.dialog','ngResource']);

myApp.controller('TestCtrl', function($scope,$dialog,TestResource) { 
 $scope.obj = {};
 $scope.obj.firstname = "Mahatma";
 $scope.obj.lastname = "Gandhi";

 $scope.storedata = function() {
    console.log("Storing Data now");
    TestResource.save($scope.obj);
    console.log("Data should have been stored");
 }
});


myApp.factory('TestResource', ['$resource', function($resource) {
  return $resource('test.json', {}, {} );
}]);

The problem is that the data does not get stored. Am I missing something here ? Here is a plunkr : http://plnkr.co/edit/gist:3662702