adds version meta tag

Author: niquerio

views/layout.erb

@@ -20,6 +20,7 @@
     <!-- End Google Tag Manager -->
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width">
+    <meta name="version" content="<%=(ENV["APP_VERSION"] || "APP_VERSION")%>">
     <title>Get This <% if defined?(item) %> "<%= item.title %>" <% end %>| University of Michigan Library</title>
     <link rel="icon" type="image/svg+xml" href="/favicon.svg">