Switch pkg packages, pub, and dartdoc to use package: imports.

pkg/scheduled_test/test/value_future_test.dart

 // Copyright (c) 2013, 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 value_future_test;
 
 import 'dart:async';
 
-import '../lib/src/value_future.dart';
-import '../../../pkg/unittest/lib/unittest.dart';
+import 'package:scheduled_test/src/value_future.dart';
+import 'package:unittest/unittest.dart';
 
 void main() {
   group('works like a normal Future for', () {
     var completer;
     var future;
 
     setUp(() {
       completer = new Completer();
       future = new ValueFuture(completer.future);
     });
@@ skipping 97 matching lines @@
 
     test('.value is null', () {
       expect(future.value, isNull);
     });
 
     test('.hasValue is false', () {
       expect(future.hasValue, isFalse);
     });
   });
 }