refactor: upgrade to NodeJS 8, Angular 6, CLI 6, Electron 2.0, RxJS 6.1

src/test.ts

@@ -6,8 +6,6 @@ import {
   BrowserDynamicTestingModule,
   platformBrowserDynamicTesting
 } from '@angular/platform-browser-dynamic/testing';
-import { Observable } from 'rxjs/Observable';
-import { TranslateLoader, TranslateService } from '@ngx-translate/core';
 
 declare const require: any;
 

src/tsconfig.spec.json

@@ -11,7 +11,8 @@
     ]
   },
   "files": [
-    "test.ts"
+    "test.ts",
+    "polyfills.ts"
   ],
   "include": [
     "**/*.spec.ts",