totp => otp, integrate with factors, new setup form

passbook/lib/boilerplate.py

@@ -0,0 +1,12 @@
+"""passbook django boilerplate code"""
+from django.utils.decorators import method_decorator
+from django.views.decorators.cache import never_cache
+
+
+class NeverCacheMixin():
+    """Use never_cache as mixin for CBV"""
+
+    @method_decorator(never_cache)
+    def dispatch(self, *args, **kwargs):
+        """Use never_cache as mixin for CBV"""
+        return super().dispatch(*args, **kwargs)