Refactor API URLs to use GlobalConstants and update CORS configurations for production

jambotron-ui/src/app/global-constants.spec.ts

@@ -0,0 +1,7 @@
+import { GlobalConstants } from './global-constants';
+
+describe('GlobalConstants', () => {
+  it('should create an instance', () => {
+    expect(new GlobalConstants()).toBeTruthy();
+  });
+});