admin: add generic create and delete template

passbook/admin/templates/generic/form.html

@@ -1,7 +1,7 @@
 {% extends "administration/base.html" %}
 
-{% load crispy_forms_tags %}
 {% load i18n %}
+{% load utils %}
 
 {% block content %}
 <div class="container">
@@ -10,6 +10,7 @@
   <div class="">
     <form action="" method="post" class="form-horizontal">
       {% include 'blocks/form.html' with form=form %}
+      <a class="btn btn-default" href="{% back %}">{% trans "Cancel" %}</a>
       <input type="submit" class="btn btn-primary" value="{% trans 'Create' %}" />
     </form>
   </div>