fix(test): create polyfills-test.ts for karma test & setup Travis CI

src/karma.conf.js

@@ -0,0 +1,31 @@
+// Karma configuration file, see link for more information
+// https://karma-runner.github.io/0.13/config/configuration-file.html
+
+module.exports = function (config) {
+  config.set({
+    basePath: '',
+    frameworks: ['jasmine', '@angular-devkit/build-angular'],
+    plugins: [
+      require('karma-jasmine'),
+      require('karma-chrome-launcher'),
+      require('karma-jasmine-html-reporter'),
+      require('karma-coverage-istanbul-reporter'),
+      require('@angular-devkit/build-angular/plugins/karma')
+    ],
+    client:{
+      clearContext: false // leave Jasmine Spec Runner output visible in browser
+    },
+    coverageIstanbulReporter: {
+      dir: require('path').join(__dirname, '../coverage'),
+      reports: [ 'html', 'lcovonly' ],
+      fixWebpackSourcePaths: true
+    },
+    reporters: ['progress', 'kjhtml'],
+    port: 9876,
+    colors: true,
+    logLevel: config.LOG_INFO,
+    autoWatch: true,
+    browsers: ['Chrome'],
+    singleRun: true
+  });
+};