Fix HERB violation

Author: rafaelfranca

app/views/layouts/application.html.erb

@@ -5,7 +5,7 @@
     <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
     <meta name="description" content="<%= @description %>">
     <meta name="keywords" content="<%= Array.wrap(@keywords).concat(['Ruby on Rails', 'core', 'contributors']).join(',') %>">
-    <meta name="viewport" content="width=device-width,initial-scale=1" />
+    <meta name="viewport" content="width=device-width,initial-scale=1">
     <meta name="author" content="Xavier Noria">
     <meta name="designer" content="José Espinal">