Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/services/index/index_unit_test.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:convert';
 
 import 'package:analysis_server/src/services/index/index_unit.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/summary/format.dart';
 import 'package:analyzer/src/summary/idl.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../../abstract_single_unit.dart';
 
 main() {
-  groupSep = ' | ';
-  defineReflectiveTests(PackageIndexAssemblerTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(PackageIndexAssemblerTest);
+  });
 }
 
 class ExpectedLocation {
   final CompilationUnitElement unitElement;
   final int offset;
   final int length;
   final bool isQualified;
 
   ExpectedLocation(
       this.unitElement, this.offset, this.length, this.isQualified);
@@ skipping 1301 matching lines @@
   final bool isQualified;
 
   _Relation(this.kind, this.offset, this.length, this.isQualified);
 
   @override
   String toString() {
     return '_Relation{kind: $kind, offset: $offset, length: $length, '
         'isQualified: $isQualified}';
   }
 }