fix typo

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/ParentControllerTest.java

 	}
 
 	@Test
-	public void destory_DestorysChildren() throws Exception {
+	public void destroy_DestroysChildren() throws Exception {
 		ViewController child1 = spy(new SimpleViewController(activity, "child1"));
 		children.add(child1);