switch buildbot to use the new test runner
switch buildbot to use the new test runner

dart-lang/dart-protobuf,dart-lang/dart-protobuf,google/protobuf.dart,dart-lang/protobuf,dart-lang/dart-protobuf,google/protobuf.dart,dart-lang/protobuf,collinjackson/dart-protobuf,google/protobuf.dart,dart-lang/protobuf