Write the given contents to the specified file. This is not
        an append, all file contents will be replaced by the contents
        given.

def post(self, filepath):
        """
        Write the given contents to the specified file. This is not
        an append, all file contents will be replaced by the contents
        given.
        """
        try:
            content = self.get_body_argument('content')
            self.fs.write_file(filepath, content)
            self.write({'msg': 'Updated file at {}'.format(filepath)})
        except OSError:
            raise tornado.web.HTTPError(404)