Add support for swarm init lock and swarm unlock

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

client/swarm_unlock.go

@@ -0,0 +1,17 @@
+package client
+
+import (
+	"github.com/docker/docker/api/types/swarm"
+	"golang.org/x/net/context"
+)
+
+// SwarmUnlock unlockes locked swarm.
+func (cli *Client) SwarmUnlock(ctx context.Context, req swarm.UnlockRequest) error {
+	serverResp, err := cli.post(ctx, "/swarm/unlock", nil, req, nil)
+	if err != nil {
+		return err
+	}
+
+	ensureReaderClosed(serverResp)
+	return err
+}