[enzyme] Bump TypeScript version to 3.1

types/enzyme/index.d.ts

@@ -10,7 +10,7 @@
 //                 Martin Hochel <https://github.com/hotell>
 //                 Christian Rackerseder <https://github.com/screendriver>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-// TypeScript Version: 2.8
+// TypeScript Version: 3.1
 
 /// <reference types="cheerio" />
 import { ReactElement, Component, AllHTMLAttributes as ReactHTMLAttributes, SVGAttributes as ReactSVGAttributes } from "react";