Fix registering "/" endpoint

utils.go

@@ -4,7 +4,7 @@ package simplerouter
 // Makes sure the patterns are in the right format
 // That is, always a leading slash, and no trailing slashes
 func cleanPattern(pattern string) string {
-	if len(pattern) == 0 {
+	if len(pattern) == 0 || pattern == "/" {
 		return "/"
 	}