Switch to new vendor directory layout

Fixes #113

Signed-off-by: Marcos Lilljedahl <marcosnils@gmail.com>

vendor/github.com/opencontainers/runc/libcontainer/error_test.go

@@ -0,0 +1,20 @@
+package libcontainer
+
+import "testing"
+
+func TestErrorCode(t *testing.T) {
+	codes := map[ErrorCode]string{
+		IdInUse:            "Id already in use",
+		InvalidIdFormat:    "Invalid format",
+		ContainerPaused:    "Container paused",
+		ConfigInvalid:      "Invalid configuration",
+		SystemError:        "System error",
+		ContainerNotExists: "Container does not exist",
+	}
+
+	for code, expected := range codes {
+		if actual := code.String(); actual != expected {
+			t.Fatalf("expected string %q but received %q", expected, actual)
+		}
+	}
+}