Return to URI slash instead of OS file separator

[mauriarroqui]

We need to rollback (#666) to URI format slash, that change broke raml 08 parsing on Windows as it uses backslash. In RAML, paths are unix-like (forward slash). APIKIT needed that change to resolve includes inside XSD files in which other XSD files can be included in a file path way (not URI). However, that change didn’t resolve their issue completely, it is still failing.

[jpbelang]

Could you check #675 ? If it isn't what you mean, I'll merge your rollback.

[mauriarroqui]

I guess it is not that fix. i.e param path in getParentPath(String path) is relative path (I don't know if a relative path could came as param) in a windows machine like a/b/c.raml, it is not an URI, so it will look for last index of \, and will return -1.