Only run checkpoint test if criu is installed

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

checkpoint_test.go

@@ -10,6 +10,9 @@ func TestCheckpointRestore(t *testing.T) {
 	if testing.Short() {
 		t.Skip()
 	}
+	if !supportsCriu {
+		t.Skip("system does not have criu installed")
+	}
 	client, err := New(address)
 	if err != nil {
 		t.Fatal(err)
@@ -100,6 +103,9 @@ func TestCheckpointRestoreNewContainer(t *testing.T) {
 	if testing.Short() {
 		t.Skip()
 	}
+	if !supportsCriu {
+		t.Skip("system does not have criu installed")
+	}
 	client, err := New(address)
 	if err != nil {
 		t.Fatal(err)

client_test.go

@@ -21,6 +21,7 @@ const (
 var (
 	address      string
 	noDaemon     bool
+	supportsCriu bool
 )
 
 func init() {
@@ -33,6 +34,11 @@ func TestMain(m *testing.M) {
 	if testing.Short() {
 		os.Exit(m.Run())
 	}
+
+	// check if criu is installed on the system
+	_, err := exec.LookPath("criu")
+	supportsCriu = err == nil
+
 	var (
 		cmd *exec.Cmd
 		buf = bytes.NewBuffer(nil)