Bump libcompose and its dependencies

vendor/github.com/docker/engine-api/client/container_attach.go

@@ -0,0 +1,34 @@
+package client
+
+import (
+	"net/url"
+
+	"github.com/docker/engine-api/types"
+	"golang.org/x/net/context"
+)
+
+// ContainerAttach attaches a connection to a container in the server.
+// It returns a types.HijackedConnection with the hijacked connection
+// and the a reader to get output. It's up to the called to close
+// the hijacked connection by calling types.HijackedResponse.Close.
+func (cli *Client) ContainerAttach(ctx context.Context, container string, options types.ContainerAttachOptions) (types.HijackedResponse, error) {
+	query := url.Values{}
+	if options.Stream {
+		query.Set("stream", "1")
+	}
+	if options.Stdin {
+		query.Set("stdin", "1")
+	}
+	if options.Stdout {
+		query.Set("stdout", "1")
+	}
+	if options.Stderr {
+		query.Set("stderr", "1")
+	}
+	if options.DetachKeys != "" {
+		query.Set("detachKeys", options.DetachKeys)
+	}
+
+	headers := map[string][]string{"Content-Type": {"text/plain"}}
+	return cli.postHijacked(ctx, "/containers/"+container+"/attach", query, nil, headers)
+}