Use local copy of persona's include.js in dev environment

app/views/layouts/application.html.slim

@@ -5,9 +5,12 @@ html[lang="en"]
     title = page_title
     = csrf_meta_tags
     = stylesheet_link_tag "application", :media => "all"
-    = javascript_include_tag "https://login.persona.org/include.js"
     = javascript_include_tag "application"
     = javascript_include_tag "player"
+    - if Rails.env.development?
+      = javascript_include_tag "persona-include.js"
+    - else
+      = javascript_include_tag "https://login.persona.org/include.js"
     = favicon_link_tag 'favicon.png'
     = render :partial => 'layouts/ga'
     script