matchers.go
func NewPathRedirect(path string) PathRedirect {
	if !strings.HasPrefix(path, "/") {
		path = "/" + path
	}
	return PathRedirect(path)
}
func NewPathRedirect(path string) PathRedirect {
	if !strings.HasPrefix(path, "/") {
		path = "/" + path
	}
	return PathRedirect(path)
}
// PathRedirect ---------------------------------------------------------------
// NewPathRedirect returns a static URL path matcher that redirects if the
// trailing slash differs.