upgrade dependencies, including migration to package:test

test/checker/checker_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.
 
 /// General type checking tests
 library dev_compiler.test.checker_test;
 
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 
 import 'package:dev_compiler/src/testing.dart';
 
-import '../test_util.dart';
-
 void main() {
-  configureTest();
-
   test('ternary operator', () {
     testChecker({
       '/main.dart': '''
         abstract class Comparable<T> {
           int compareTo(T other);
           static int compare(Comparable a, Comparable b) => a.compareTo(b);
         }
         typedef int Comparator<T>(T a, T b);
 
         typedef bool _Predicate<T>(T value);
@@ skipping 2902 matching lines @@
             f = bar as II2D;
             f = bar as DD2I;
             f = bar as DI2D;
             f = bar as ID2D;
             f = bar as DD2D;
           }
       '''
     });
   });
 }