refactored app structure

app/templates/404.html

@@ -0,0 +1,14 @@
+{% extends "base.html" %}
+
+{% block meta %}
+{{ super() }}
+<!-- Add additional meta tags here -->
+{% endblock %}
+
+{% block title %}Testing{% endblock %}
+
+{% block page_content %}
+<div class="page-header">
+    <h1>Opps! File not found</h1>
+</div>
+{% endblock %}