Added test utility from SKY UX (#382)

* Added test utility from SKY UX

* Separated event options into separate file

Author: Blackbaud-SteveBrush

runtime/testing/browser/index.ts

@@ -1,2 +1,3 @@
 export * from './matchers';
 export * from './test-module';
+export * from './test-utility';

runtime/testing/browser/test-utility-dom-event-options.ts

@@ -0,0 +1,4 @@
+export interface SkyAppTestUtilityDomEventOptions {
+  bubbles?: boolean;
+  cancelable?: boolean;
+}

runtime/testing/browser/test-utility.ts

@@ -0,0 +1,17 @@
+import { SkyAppTestUtilityDomEventOptions } from './test-utility-dom-event-options';
+
+export class SkyAppTestUtility {
+  public static fireDomEvent(
+    element: EventTarget,
+    eventName: string,
+    options?: SkyAppTestUtilityDomEventOptions
+  ) {
+    const defaults = { bubbles: true, cancelable: true };
+    const { bubbles, cancelable } = Object.assign({}, defaults, options);
+
+    const event = document.createEvent('CustomEvent');
+    event.initEvent(eventName, bubbles, cancelable);
+
+    element.dispatchEvent(event);
+  }
+}