Separate go module for client tests

Will help us drop dependency to github.com/Microsoft/hcsshim/test in the
main go.mod

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

integration/client/snapshot_test.go

@@ -0,0 +1,51 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package containerd
+
+import (
+	"context"
+	"runtime"
+	"testing"
+
+	. "github.com/containerd/containerd"
+	"github.com/containerd/containerd/snapshots"
+	"github.com/containerd/containerd/snapshots/testsuite"
+)
+
+func newSnapshotter(ctx context.Context, root string) (snapshots.Snapshotter, func() error, error) {
+	client, err := New(address)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	sn := client.SnapshotService(DefaultSnapshotter)
+
+	return sn, func() error {
+		// no need to close remote snapshotter
+		return client.Close()
+	}, nil
+}
+
+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)
+}