Switch analysis_server to use 'package:test'.

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

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.integration.analysis.analysis_options_test;
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analyzer/src/generated/engine.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(OptionsIntegrationTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(OptionsIntegrationTest);
+  });
 }
 
 @reflectiveTest
 class OptionsIntegrationTest extends AbstractAnalysisServerIntegrationTest {
   test_option_warning_newOptionFile() async {
     String options = sourcePath(AnalysisEngine.ANALYSIS_OPTIONS_YAML_FILE);
     writeFile(
         options,
         '''
 linter:
@@ skipping 38 matching lines @@
     AnalysisError error = errors[0];
     expect(error.location.file, options);
     expect(error.severity, AnalysisErrorSeverity.WARNING);
     expect(error.type, AnalysisErrorType.STATIC_WARNING);
     expect(error.location.offset, 23);
     expect(error.location.length, 'camel_case_typo'.length);
     expect(error.location.startLine, 3);
     expect(error.location.startColumn, 7);
   }
 }