Error when absolute paths include the protocol

A colleague reminded me that #113 can fail in a very simple case, when a protocol is specified. Inside `normalize.js` you already detect absolute paths with a protocol, so instead of adding conditions inside the `if` you probably will want to generalize this in a function.

I don't have time now to propose a clean solution. I would just leave this failing test case and this pull request here, in order to help anybody that could have this problem in the future.