Move engine-api client package

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

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

client/container_unpause.go

@@ -0,0 +1,10 @@
+package client
+
+import "golang.org/x/net/context"
+
+// ContainerUnpause resumes the process execution within a container
+func (cli *Client) ContainerUnpause(ctx context.Context, containerID string) error {
+	resp, err := cli.post(ctx, "/containers/"+containerID+"/unpause", nil, nil, nil)
+	ensureReaderClosed(resp)
+	return err
+}