Update the DBIServer generator to use admin user.

test/support/generators.ex

@@ -78,7 +78,7 @@ defmodule DecentralisedBookIndex.Generators do
     actor =
       opts[:actor] ||
         once(:default_actor, fn ->
-          generate(user(role: :moderator))
+          generate(user(role: :admin))
         end)
 
     url =