add 405 error page

app/errors.py

@@ -2,13 +2,17 @@ from flask import render_template
 from app import app, db
 
 @app.errorhandler(403)
-def not_found_error(error):
+def forbidden_error(error):
     return render_template('403.html'), 403
 
 @app.errorhandler(404)
 def not_found_error(error):
     return render_template('404.html'), 404
 
+@app.errorhandler(405)
+def method_not_allowed_error(error):
+    return render_template('405.html'), 405
+
 @app.errorhandler(500)
 def internal_error(error):
     db.session.rollback()

app/templates/405.html

@@ -0,0 +1,7 @@
+{% extends "base.html" %}
+
+{% block app_content %}
+    <h1>Method Not Allowed</h1>
+    <h2>The method is not allowed for the requested URL.</h2>
+    <p><a href="{{ url_for('index') }}">Back</a></p>
+{% endblock %}