Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/services/correction/levenshtein_test.dart

Index: pkg/analysis_server/test/services/correction/levenshtein_test.dart
diff --git a/pkg/analysis_server/test/services/correction/levenshtein_test.dart b/pkg/analysis_server/test/services/correction/levenshtein_test.dart
index a1b0a92e43ddc9c9bf5152e47cba0f1265420a81..482817bd1f89401188f6fadb7cdcbd8145b073a0 100644
--- a/pkg/analysis_server/test/services/correction/levenshtein_test.dart
+++ b/pkg/analysis_server/test/services/correction/levenshtein_test.dart
@@ -5,14 +5,16 @@
 library test.services.correction.levenshtein;
 
 import 'package:analysis_server/src/services/correction/levenshtein.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(LevenshteinTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(LevenshteinTest);
+  });
 }
 
 @reflectiveTest