Fix wrong awarding user for automatic artist badge award

lib/philomena/artist_links.ex

@@ -93,7 +93,7 @@ defmodule Philomena.ArtistLinks do
 
     Multi.new()
     |> Multi.update(:artist_link, artist_link_changeset)
-    |> Multi.run(:add_award, fn _repo, _changes -> BadgeAwarder.award_badge(artist_link) end)
+    |> Multi.run(:add_award, BadgeAwarder.award_callback(artist_link, verifying_user))
     |> Repo.transaction()
     |> case do
       {:ok, %{artist_link: artist_link}} ->

lib/philomena/artist_links/badge_awarder.ex

@@ -16,13 +16,22 @@ defmodule Philomena.ArtistLinks.BadgeAwarder do
   Returns `{:ok, award}`, `{:ok, nil}`, or `{:error, changeset}`. The return value is
   suitable for use as the return value to an `Ecto.Multi.run/3` callback.
   """
-  def award_badge(artist_link) do
+  def award_badge(artist_link, verifying_user) do
     with badge when not is_nil(badge) <- Badges.get_badge_by_title(@badge_title),
          award when is_nil(award) <- Badges.get_badge_award_for(badge, artist_link.user) do
-      Badges.create_badge_award(artist_link.user, artist_link.user, %{badge_id: badge.id})
+      Badges.create_badge_award(verifying_user, artist_link.user, %{badge_id: badge.id})
     else
       _ ->
         {:ok, nil}
     end
   end
+
+  @doc """
+  Get a callback for issuing a badge award from within an `m:Ecto.Multi`.
+  """
+  def award_callback(artist_link, verifying_user) do
+    fn _repo, _changes ->
+      award_badge(artist_link, verifying_user)
+    end
+  end
 end