update: preserve the AllFiles flag in the new manifest

update.go

diff --git a/update.go b/update.go
index 8d71ae6..ac462fd 100644
--- a/update.go
+++ b/update.go
@@ -97,6 +97,7 @@
 				Branch:     branch,
 				Path:       extra,
 				NoTests:    d.NoTests,
+				AllFiles:   d.AllFiles,
 			}
 
 			if err := fileutils.RemoveAll(filepath.Join(vendorDir(), filepath.FromSlash(d.Importpath))); err != nil {