### One-sentence description Crash on registration renew page ### Current behaviour ``` File "/usr/local/lib/python3.5/site-packages/django/core/handlers/exception.py" in inner 35. response = get_response(request) File "/usr/local/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response 128. response = self.process_exception_by_middleware(e, request) File "/usr/local/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response 126. response = wrapped_callback(request, *callback_args, **callback_kwargs) File "/usr/local/lib/python3.5/site-packages/django/views/generic/base.py" in view 69. return self.dispatch(request, *args, **kwargs) File "/usr/local/lib/python3.5/site-packages/django/utils/decorators.py" in _wrapper 62. return bound_func(*args, **kwargs) File "/usr/local/lib/python3.5/site-packages/django/contrib/auth/decorators.py" in _wrapped_view 21. return view_func(request, *args, **kwargs) File "/usr/local/lib/python3.5/site-packages/django/utils/decorators.py" in bound_func 58. return func.__get__(self, type(self))(*args2, **kwargs2) File "/usr/local/lib/python3.5/site-packages/django/views/generic/base.py" in dispatch 89. return handler(request, *args, **kwargs) File "/usr/local/lib/python3.5/site-packages/django/views/generic/edit.py" in get 133. return self.render_to_response(self.get_context_data()) File "./registrations/views.py" in get_context_data 143. c[1] for c in Membership.MEMBERSHIP_TYPES File "./registrations/views.py" in <listcomp> 144. if c[0] == context['membership'].type Exception Type: AttributeError at /registration/renew/ Exception Value: 'NoneType' object has no attribute 'type' Request information: USER: azijlstra ``` ### Expected behaviour No crash ### Steps to reproduce Unknown