upgrade dependencies, including migration to package:test

lib/src/testing.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 dev_compiler.src.testing;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
 import 'package:logging/logging.dart';
 import 'package:source_span/source_span.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 
 import 'package:dev_compiler/config.dart';
 import 'package:dev_compiler/devc.dart' show Compiler;
 
 import 'analysis_context.dart';
 import 'dependency_graph.dart' show runtimeFilesForServerMode;
 import 'info.dart';
 import 'options.dart';
 import 'report.dart';
 import 'utils.dart';
@@ skipping 276 matching lines @@
     expect(tokens[1], "should", reason: 'invalid error descriptor');
     expect(tokens[2], "be", reason: 'invalid error descriptor');
     if (tokens[0] == "pass") return null;
     // TODO(leafp) For now, we just use whatever the current expectation is,
     // eventually we could do more automated reporting here.
     return _parse(tokens[0]);
   }
 
   String toString() => '$level $type';
 }