update vendor

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

vendor/github.com/genuinetools/reg/registry/customtransport.go

@@ -0,0 +1,24 @@
+package registry
+
+import (
+	"net/http"
+)
+
+// CustomTransport defines the data structure for custom http.Request options.
+type CustomTransport struct {
+	Transport http.RoundTripper
+	Headers   map[string]string
+}
+
+// RoundTrip defines the round tripper for the error transport.
+func (t *CustomTransport) RoundTrip(request *http.Request) (*http.Response, error) {
+	if len(t.Headers) != 0 {
+		for header, value := range t.Headers {
+			request.Header.Add(header, value)
+		}
+	}
+
+	resp, err := t.Transport.RoundTrip(request)
+
+	return resp, err
+}