Add a test to make sure we are root before starting the tests on docker package

docker_test.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"os"
 	"os/exec"
+	"os/user"
 	"testing"
 )
 
@@ -42,6 +43,12 @@ func init() {
 		return
 	}
 
+	if usr, err := user.Current(); err != nil {
+		panic(err)
+	} else if usr.Uid != "0" {
+		panic("docker tests needs to be run as root")
+	}
+
 	// Create a temp directory
 	root, err := ioutil.TempDir("", "docker-test")
 	if err != nil {