Added Support for Basic Auth in URLs

* Added basic auth support for URL's with [RFC-1738](http://tools.ietf.org/html/rfc1738#section-3.1) `username:password` syntax.
* Updated unit tests for [Mocha 4.x compatibility](https://github.com/shouldjs/should.js/wiki/Breaking-changes-4.x) (replaced `include` with `containEql`)
* Added unit tests for basic auth in URLs