too many arguments in call to append

After using your code for ages, suddenly started seeing this error:

```
./qthulhu_test.go:19: too many arguments in call to append
./qthulhu_test.go:19: append([]interface {} literal, v...) used as value
```

Which is this line:

```
fmt.Printf("\033[31m%s:%d: "+msg+"\033[39m\n\n", append([]interface{}{filepath.Base(file), line}, v...)...)
```
