Fix hugo serve / jquery.js

[gjenkins8]

Currently hugo serve locally reports the following error. Unsure as to why, but somehow the vendered jquery is invalid. This PR bumps to the latest v2 jquery (TBD: reference source)

$  hugo serve
...
Error: error building site: MINIFY: failed to transform "js/jquery.js" (text/javascript): unexpected /*!
 * Sizzle CSS Selector Engine v1.10.19
 * http://sizzlejs.com/
 *
 * Copyright 2013 jQuery Foundation, Inc. and other contributors
 * Released under the MIT license
 * http://jquery.org/license
 *
 * Date: 2014-04-18
 */ in expression on line 14 and column 13202
   14: ...object "+b+"]"]=b.toLowerCase()});var eb=/*!
                                                   ^

[gjenkins8]

fixes: #1539