Remove JSZip.version because we will never manage to keep it correct

We always load JSZip from pinned npm package so there's never ambiguity
about the version. Just look at package-lock.json.

Author: GarboMuffin

lib/index.js

@@ -43,10 +43,6 @@ JSZip.prototype.loadAsync = require("./load");
 JSZip.support = require("./support");
 JSZip.defaults = require("./defaults");
 
-// TODO find a better way to handle this version,
-// a require('package.json').version doesn't work with webpack, see #327
-JSZip.version = "3.10.1";
-
 JSZip.loadAsync = function (content, options) {
     return new JSZip().loadAsync(content, options);
 };