Suggestion: 'to yield exchanges [satisfying]'

[msiebuhr]

After getting into testing some non-idempodent flows I ended up missing something like this:

expect(foo, 'to yield exchanges satisfying', [{
    request: {...},
    response: {...}
}, {
    request: {...},
    response: {...}
}]);

Basically short-hand for

expect(foo, 'to yield exchange satisfying', {...})
    .then(function () {
         return expect(foo, 'to yield excchange satisfying', {...});
     });

[papandreou]

Certainly doable, haven't needed it much myself, though. PR welcome :)