Use Angular CLI instead of ngm for building

Some commands:

npm run build      - to build the library.  Output is in dist/ng2-file-upload/.
npm run test       - to run tests.  Coverage report is in coverage/ as before.
npm run demo.serve - to build demo application and serve it through browsersync
npm run start      - to run demo application using `ng serve`.  Requires the library to be built and linked first.

test/test.ts

@@ -0,0 +1,37 @@
+import '../scripts/polyfills.ts';
+
+import 'zone.js/dist/long-stack-trace-zone';
+import 'zone.js/dist/proxy.js';
+import 'zone.js/dist/sync-test';
+import 'zone.js/dist/jasmine-patch';
+import 'zone.js/dist/async-test';
+import 'zone.js/dist/fake-async-test';
+import { getTestBed } from '@angular/core/testing';
+import {
+  BrowserDynamicTestingModule,
+  platformBrowserDynamicTesting
+} from '@angular/platform-browser-dynamic/testing';
+
+import './matchers';
+
+// Unfortunately there's no typing for the `__karma__` variable. Just declare it as any.
+declare var __karma__: any;
+declare var require: any;
+
+// Prevent Karma from running prematurely.
+__karma__.loaded = Function.prototype;
+
+// First, initialize the Angular testing environment.
+getTestBed().initTestEnvironment(
+  BrowserDynamicTestingModule,
+  platformBrowserDynamicTesting()
+);
+// Then we find all the tests.
+let context = require.context('../demo/src', true, /\.spec\.ts/);
+// And load the modules.
+context.keys().map(context);
+
+let context2 = require.context('../src/spec', true, /\.spec\.ts/);
+context2.keys().map(context2);
+// Finally, start Karma to run the tests.
+__karma__.start();