See #132 for background.
The following is misleading and should not be allowed:
If the object should_not_receive the message, than there is no need to assign a return value.
Let's raise an error in 3.0 recommending the user remove and_return, and add a deprecation warning in a 2.x release with the same message.
Issue #134: Add deprecation warning for should_not_receive followed b…
Was this resolved by #151, or is it good practise to keep this open until the "behaviour" is actually removed?
Clean code generating a deprecation warning
should_not_receive can't be used with and_return