message: testing only with FF (for now)
  trying to debug CI failures
diff: @@ -92,7 +92,8 @@ module.exports = function(config) {
  // start these browsers
  // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
  - browsers: ['HeadlessChrome', 'HeadlessFirefox'],
  + // browsers: ['HeadlessChrome', 'HeadlessFirefox'],
  + browsers: ['HeadlessFirefox'],
  // Continuous Integration mode
  @@ -101,7 +102,8 @@ module.exports = function(config) {
  // Concurrency level
  // how many browser should be started simultaneous
  - concurrency: process.env.TRAVIS ? 1 : Infinity,
  + // concurrency: process.env.TRAVIS ? 1 : Infinity,
  + concurrency: Infinity,
  //custom launcher for travis
  customLaunchers: {
  @@ -113,7 +115,8 @@ module.exports = function(config) {
  base: 'Firefox',
  flags: [ '-headless' ],
  prefs: {
  - 'media.navigator.permission.disabled': true
  + 'media.navigator.permission.disabled': true,
  + 'focusmanager.testmode': true
  }
  }
  }
  