Fixed karma tests during build

Added logging to karma browser detection

karma.conf.js

@@ -39,17 +39,22 @@ module.exports = function (config) {
     detectBrowsers: {
       postDetection: function (browsers) {
         // When overriden, use command line
-        if (config.browsers) {
+        if (config.browsers && config.browsers.length) {
+          console.log('Using browsers from command-line argument', config.browsers);
           return config.browsers;
         }
 
         // Run in headless mode
-        return browsers.map(function (b) {
+        browsers = browsers.map(function (b) {
           if (b === 'Chrome' || b === 'Firefox') {
             return b + 'Headless';
           }
           return b;
         });
+
+        // Log and return
+        console.log('Using filtered detected browsers', browsers);
+        return browsers;
       }
     }
   });