workaround: Running ng test in windows fails with EMFILE error

see angular/angular-cli#977

Author: JohannesHoppe

book-rating/package.json

@@ -7,7 +7,7 @@
     "start": "ng serve",
     "postinstall": "typings install",
     "lint": "tslint \"src/**/*.ts\"",
-    "test": "ng test",
+    "test": "ng build && ng test --build=false",
     "pree2e": "webdriver-manager update",
     "e2e": "protractor"
   },