message: don't always include default browsers
diff: @@ -24,7 +24,7 @@ var BROWSER_SPEC = /^([^\/@]+)\/([^\/@]+)(?:@(.*))?$/;
  function expand(pluginOptions, done) {
  var browsers = pluginOptions.browsers;
  // 'all' is really 'default', just to be consistent with wct-local.
  - if (browsers.indexOf('default') !== -1 || browsers.indexOf('all')) {
  + if (browsers.indexOf('default') !== -1 || browsers.indexOf('all') !== -1) {
  // TODO(nevir): Figure out the latest version of each browser and pick
  // appropriate spreads of versions & OSes.
  browsers = browsers.concat(_.cloneDeep(DEFAULT_BROWSERS));
  