PhantomJS process hangs after VS 2012 build

My environment is using VS 2012 to run a Grunt task that has Jasmine tests. These tests use PhantomJS to execute during the build process. After the tests complete (both successfully and/or unsuccessfully) the PhantomJS process stays loaded. This is the flow of events:

1) Start a local build of the Visual studio project. Here is my grunt task that is executing during the Visual Studio build process:

VS 2012 csproj file xml

and here is my (simplified) grunt.js task:

module.exports = function (grunt) {

// Project Config //
grunt.initConfig({
    // Unit testing framework //
    jasmine: {
        pivotal: {
            src: ['./*.js'],
            options: {
                vendor: ['scripts/*.js'],
                specs: 'tests/specs/*.js'
            }
        }
    }
});

grunt.loadNpmTasks('grunt-contrib-jasmine');
grunt.loadNpmTasks('grunt-jasmine-node');

grunt.registerTask('default', ['jasmine']);

2) Upon the build completion open the Windows Task Manager and notice that the PhantomJS.exe is still loaded in memory

Windows Task Manager and PhantomJS processes

I would like suggestions on how to programatically kill this process when the VS build is finished and/or a fix to the issue using a defined Grunt/Jasmine/Node command?

Thanks