Make assets depend on RE.
diff --git a/rol-assets.asd b/rol-assets.asd
index 0c72495..ad2621e 100644
--- a/rol-assets.asd
+++ b/rol-assets.asd
@@ -40,6 +40,7 @@
"external-program"
"ironclad"
"positional"
+ "re"
"rol-files"
"rol-uri"
"str")