[added] createSelectedEvent for consistent onSelect handling

Related to react-bootstrap#419

Author: mtscout6

src/utils/createSelectedEvent.js

@@ -0,0 +1,15 @@
+export default function createSelectedEvent(eventKey) {
+  let selectionPrevented = false;
+
+  return {
+    eventKey,
+
+    preventSelection() {
+      selectionPrevented = true;
+    },
+
+    isSelectionPrevented() {
+      return selectionPrevented;
+    }
+  };
+}