Compute path given current file and relative path.

def relpath(self, current_file, rel_path):
        """
        Compute path given current file and relative path.
        """
        script_dir = os.path.dirname(os.path.abspath(current_file))
        rel_path = os.path.abspath(os.path.join(script_dir, rel_path))
        return rel_path