Move engine-api client package

This moves the engine-api client package to `/docker/docker/client`.

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

swarm_init.go

@@ -0,0 +1,21 @@
+package client
+
+import (
+	"encoding/json"
+
+	"github.com/docker/docker/api/types/swarm"
+	"golang.org/x/net/context"
+)
+
+// SwarmInit initializes the Swarm.
+func (cli *Client) SwarmInit(ctx context.Context, req swarm.InitRequest) (string, error) {
+	serverResp, err := cli.post(ctx, "/swarm/init", nil, req, nil)
+	if err != nil {
+		return "", err
+	}
+
+	var response string
+	err = json.NewDecoder(serverResp.body).Decode(&response)
+	ensureReaderClosed(serverResp)
+	return response, err
+}