Add npm test to travis ci

test/karma.conf.js

@@ -0,0 +1,24 @@
+module.exports = function(config) {
+    config.set({
+        basePath: '../',
+        frameworks: ['mocha', 'chai', 'sinon-chai'],
+        files: [
+            './libraries/jquery-2.1.4.min.js',
+            './libraries/bluebird.min.js',
+            './src/js/serial.js',
+            './src/js/data_storage.js',
+            './src/js/localization.js',
+            './src/js/gui.js',
+            './src/js/tabs/cli.js',
+            './test/**/*.js'
+        ],
+        browsers: ['ChromeHeadlessNoSandbox'],
+        customLaunchers: {
+            ChromeHeadlessNoSandbox: {
+                base: 'ChromeHeadless',
+                flags: ['--no-sandbox']
+            }
+        },
+        singleRun: true
+    });
+};