* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test
* Adding a setup function for hot restart that can be overwritten to perform any necessary initialization before a restart is started.
* Adding a test for setupHotRestart
* Removing local pubspec change
* Fixing some type annotation errors
* Responding to comments
