Merge pull request #6236 from ampext/react-oncontextmenu-patch

added onContextMenu attribute to react DOMAttributesBase

react/react.d.ts

@@ -354,6 +354,7 @@ declare namespace __React {
         onInput?: FormEventHandler;
         onSubmit?: FormEventHandler;
         onClick?: MouseEventHandler;
+        onContextMenu?: MouseEventHandler;
         onDoubleClick?: MouseEventHandler;
         onDrag?: DragEventHandler;
         onDragEnd?: DragEventHandler;