Add version number to honeybadger.js file comment

[zmillman]

This is a pretty standard practice which makes it easier for developers to see what version of the javascript they've copied into their application.

I assume that most Rails developers will actually be copying the un-minified source to an assets folder and letting their asset compiler handle the minification with the rest of their application code. For the developers who use the straight minified version, they should still be able to figure out what version they have without doing a file-search.

Here's an example from jquery.cookie.js:

/*!
 * jQuery Cookie Plugin v1.3.1
 * https://github.com/carhartl/jquery-cookie
 *
 * Copyright 2013 Klaus Hartl
 * Released under the MIT license
 */