Simplify calls to render partial

We're also adding a bit of consistency, since most of our calls to
partial rendering omit the `partial` and `locals` keys.

app/views/layouts/application.html.erb

@@ -22,7 +22,7 @@
     <h1 class="show-for-sr"><%= setting["org_name"] %></h1>
 
     <div class="wrapper <%= yield (:wrapper_class) %>">
-      <%= render partial: "layouts/header", locals: { with_subnavigation: true } %>
+      <%= render "layouts/header", with_subnavigation: true %>
 
       <!--[if lt IE 9]>
       <% if browser.ie? && cookies["ie_alert_closed"] != "true" %>