add ticket purchase page

Co-authored-by: Jan-Marlon Leibl <jleibl@proton.me>
Reviewed-on: http://git.simonis.lol/projects/abiball/pulls/13
Reviewed-by: jank1619 <jan@kjan.email>

templates/ticket/success.html.twig

@@ -0,0 +1,16 @@
+{% extends 'base.html.twig' %}
+
+{% block title %}
+Success
+{% endblock %}
+
+{% block body %}
+<div class="container">
+    <div class="row">
+        <div class="col-md-12">
+            <h1 class="text-center">Success</h1>
+            <p class="text-center">Your ticket has been successfully created.</p>
+        </div>
+    </div>
+</div>
+{% endblock %}