Internationalize Views::Error templates

lib/gollum/locales/en.yml

@@ -6,3 +6,5 @@ en:
     comparing_versions_of: Comparing versions of
     comparing_from: "Comparing %{before} to %{after}"
     revert: Revert Changes
+  precious/views/error:
+    error: Error

lib/gollum/templates/error.mustache

@@ -1,6 +1,6 @@
 <div id="wiki-wrapper" class="error">
   <div id="error">
-    <h1>Error</h1>
+    <h1>{{t.error}}</h1>
     <p>
       {{message}}
     </p>