* Change async stubbing to use thenAnswer.
Mockito now prohibits calling thenReturn with Futures and Streams. dart-lang/mockito#79
* Update all Mockito deps to 3.0.0.
* Revert "Update all Mockito deps to 3.0.0."
This reverts commit e8ab9d37c3.
I did not correctly update the mockito dep, and there's no easy way to update to 3.0 alpha right now.
* Change thenAnswer((_) => to thenAnswer((invocation) =>
* Add Invocation type to thenAnswer lambdas
This makes command validation happen as part of `verifyThenRunCommand()`,
using a newly introduced protected method (`validateCommand()`) rather than
a `commandValidator` property (that subclasses were responsible for manually
invoking).
