fix(test):add ts MIME type

Fix angular#2125
Close angular#2175

Author: jtsom

packages/angular-cli/blueprints/ng2/files/karma.conf.js

@@ -17,6 +17,9 @@ module.exports = function (config) {
     preprocessors: {
       './<%= sourceDir %>/test.ts': ['angular-cli']
     },
+    mime: {
+      'text/x-typescript': ['ts','tsx']
+    },
     remapIstanbulReporter: {
       reports: {
         html: 'coverage',