Move engine-api client package

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

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

task_list.go

@@ -0,0 +1,35 @@
+package client
+
+import (
+	"encoding/json"
+	"net/url"
+
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/filters"
+	"github.com/docker/docker/api/types/swarm"
+	"golang.org/x/net/context"
+)
+
+// TaskList returns the list of tasks.
+func (cli *Client) TaskList(ctx context.Context, options types.TaskListOptions) ([]swarm.Task, error) {
+	query := url.Values{}
+
+	if options.Filter.Len() > 0 {
+		filterJSON, err := filters.ToParam(options.Filter)
+		if err != nil {
+			return nil, err
+		}
+
+		query.Set("filters", filterJSON)
+	}
+
+	resp, err := cli.get(ctx, "/tasks", query, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	var tasks []swarm.Task
+	err = json.NewDecoder(resp.body).Decode(&tasks)
+	ensureReaderClosed(resp)
+	return tasks, err
+}