func makeFile(c string) (fn string) {
	if f, err := ioutil.TempFile(os.TempDir(), "conf"); err == nil {
		f.WriteString(c)
		f.Close()
		return f.Name()
	} else {
		return ""
	}
}
makeFile creates a file with the given contents, returns the file
name. Returns an empty string on error.
package conf
import (
	"io/ioutil"
	"os"
	"strings"
	"testing"
)
func assert(t *testing.T, b bool) {
	if !b {
		t.Fail()
	}
}