collectiveidea/interactor — pull request #26 by ersatzryan (2014-01-26 15:43:44+00:00)
Title: Do not run peform if context failed during setup

Ran into this today

```ruby
def setup
fail! unless context[:user] = User.where(email: email).first
end

def perform
user.do_something
end
```
would error with not method error for nil, I think that perform should not be called if the setup calls `fail!`, thoughts?