move headers into dedicated folder

auth.go

@@ -10,14 +10,3 @@ func md5Hex(in string) string {
 	h.Write([]byte(in))
 	return hex.EncodeToString(h.Sum(nil))
 }
-
-// AuthMethod is an authentication method.
-type AuthMethod int
-
-const (
-	// Basic authentication method
-	Basic AuthMethod = iota
-
-	// Digest authentication method
-	Digest
-)