Skip test on windows

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

snapshot_test.go

@@ -2,6 +2,7 @@ package containerd
 
 import (
 	"context"
+	"runtime"
 	"testing"
 
 	"github.com/containerd/containerd/snapshot"
@@ -25,5 +26,8 @@ func TestSnapshotterClient(t *testing.T) {
 	if testing.Short() {
 		t.Skip()
 	}
+	if runtime.GOOS == "windows" {
+		t.Skip("snapshots not yet supported on Windows")
+	}
 	testsuite.SnapshotterSuite(t, "SnapshotterClient", newSnapshotter)
 }