karma qunit google is not defined

I'm trying to unit test an Ember application that makes use of Google Charts. I'm using a karma test runner and writing my tests with qunit. When I start the test runner as soon as it sees the first reference for google it throws this error:

Chrome 56.0.2924 (Windows 7 0.0.0) ERROR
  Uncaught ReferenceError: google is not defined
  at dist/scripts/app.js:2

I tried referencing the google charts files in my karma.conf file to no avail. Here's what that currently looks like:

module.exports = function(config) {
    config.set({
    basePath: '',
    frameworks: ['qunit'],
    files: [
      'dist/scripts/plugins.js',
      'dist/scripts/app.js',
      'dist/scripts/tests.js',
    ],

    plugins: [
      'karma-qunit',
      'karma-chrome-launcher'
    ],
    reporters: ['progress'],
    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: ['Chrome'],
    singleRun: false,
   concurrency: Infinity
  })
}