removed dead code

Signed-off-by: Sam Alba <sam.alba@gmail.com>

dagger/utils.go

@@ -1,15 +0,0 @@
-package dagger
-
-import (
-	"crypto/rand"
-	"fmt"
-)
-
-func randomID(size int) (string, error) {
-	b := make([]byte, size)
-	_, err := rand.Read(b)
-	if err != nil {
-		return "", err
-	}
-	return fmt.Sprintf("%x", b), nil
-}