message: trying with normal FF instead of headless
  timeout seems to be happening during call for requestAnimationFrame
diff: @@ -92,7 +92,7 @@ module.exports = function(config) {
  // start these browsers
  // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
  - browsers: ['HeadlessFirefox', 'HeadlessChrome'],
  + browsers: ['HeadlessChrome', process.env.TRAVIS ? 'NormalFirefox' : 'HeadlessFirefox'],
  // Continuous Integration mode
  @@ -101,7 +101,7 @@ module.exports = function(config) {
  // Concurrency level
  // how many browser should be started simultaneous
  - concurrency: 1,
  + concurrency: process.env.TRAVIS ? 1 : Infinity,
  //custom launcher for travis
  customLaunchers: {
  @@ -115,6 +115,12 @@ module.exports = function(config) {
  prefs: {
  'media.navigator.permission.disabled': true
  }
  + },
  + NormalFirefox: {
  + base: 'Firefox',
  + prefs: {
  + 'media.navigator.permission.disabled': true
  + }
  }
  }
  };
  