Add show actions for note, artist, artist commentary versions.

Add these endpoints:

* /note_versions/1234
* /artist_versions/1234
* /artist_commentary_versions/1234

This is so the /ip_addresses listing can link to these endpoints.

app/controllers/note_versions_controller.rb

@@ -6,4 +6,11 @@ class NoteVersionsController < ApplicationController
     @note_versions = @note_versions.includes(:updater) if request.format.html?
     respond_with(@note_versions)
   end
+
+  def show
+    @note_version = NoteVersion.find(params[:id])
+    respond_with(@note_version) do |format|
+      format.html { redirect_to note_versions_path(search: { note_id: @note_version.note_id }) }
+    end
+  end
 end