Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/integration/analysis/error_test.dart

Index: pkg/analysis_server/test/integration/analysis/error_test.dart
diff --git a/pkg/analysis_server/test/integration/analysis/error_test.dart b/pkg/analysis_server/test/integration/analysis/error_test.dart
index b01f1d8819e4fde9d3eaf1a84dce5e5b4124a424..9b52a482fa49ba8784f84e084e35d2ef86a0bf37 100644
--- a/pkg/analysis_server/test/integration/analysis/error_test.dart
+++ b/pkg/analysis_server/test/integration/analysis/error_test.dart
@@ -5,15 +5,17 @@
 library test.integration.analysis.error;
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../../utils.dart';
 import '../integration_tests.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(AnalysisErrorIntegrationTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(AnalysisErrorIntegrationTest);
+  });
 }
 
 @reflectiveTest