Remove barback, build and serve commands (#3833)

diff --git a/lib/src/command/barback.dart b/lib/src/command/barback.dart
deleted file mode 100644
index 9d52aa9..0000000
--- a/lib/src/command/barback.dart
+++ /dev/null
@@ -1,31 +0,0 @@
-// 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.
-
-import '../command.dart';
-import '../log.dart' as log;
-import '../utils.dart';
-
-/// Shared base class for [BuildCommand] and [ServeCommand].
-abstract class BarbackCommand extends PubCommand {
-  BarbackCommand() {
-    argParser.addOption('mode', hide: true);
-    argParser.addFlag('all', hide: true);
-    argParser.addOption('web-compiler', hide: true);
-  }
-
-  @override
-  Future<void> runProtected() async {
-    // Switch to JSON output if specified. We need to do this before parsing
-    // the source directories so an error will be correctly reported in JSON
-    // format.
-    log.json.enabled =
-        argResults.options.contains('format') && argResults['format'] == 'json';
-
-    fail(
-      log.red('Dart 2 has a new build system. Learn how to migrate '
-          "from ${log.bold('pub build')} and\n"
-          "${log.bold('pub serve')}: https://dart.dev/web/dart-2\n"),
-    );
-  }
-}
diff --git a/lib/src/command/build.dart b/lib/src/command/build.dart
deleted file mode 100644
index 8c199d6..0000000
--- a/lib/src/command/build.dart
+++ /dev/null
@@ -1,21 +0,0 @@
-// 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.
-
-import 'barback.dart';
-
-/// Handles the `build` pub command.
-class BuildCommand extends BarbackCommand {
-  @override
-  String get name => 'build';
-  @override
-  String get description => 'Deprecated command';
-  @override
-  bool get hidden => true;
-
-  BuildCommand() {
-    argParser.addOption('define', hide: true);
-    argParser.addOption('format', hide: true);
-    argParser.addOption('output', hide: true);
-  }
-}
diff --git a/lib/src/command/serve.dart b/lib/src/command/serve.dart
deleted file mode 100644
index 4c560e7..0000000
--- a/lib/src/command/serve.dart
+++ /dev/null
@@ -1,26 +0,0 @@
-// 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.
-
-import 'barback.dart';
-
-/// Handles the `serve` pub command.
-class ServeCommand extends BarbackCommand {
-  @override
-  String get name => 'serve';
-  @override
-  String get description => 'Deprecated command';
-  @override
-  bool get hidden => true;
-
-  ServeCommand() {
-    argParser.addOption('define', hide: true);
-    argParser.addOption('hostname', hide: true);
-    argParser.addOption('port', hide: true);
-    argParser.addFlag('log-admin-url', hide: true);
-    argParser.addOption('admin-port', hide: true);
-    argParser.addOption('build-delay', hide: true);
-    argParser.addFlag('dart2js', hide: true);
-    argParser.addFlag('force-poll', hide: true);
-  }
-}
diff --git a/lib/src/command_runner.dart b/lib/src/command_runner.dart
index ebaf63b..5fa9344 100644
--- a/lib/src/command_runner.dart
+++ b/lib/src/command_runner.dart
@@ -11,7 +11,6 @@
 
 import 'command.dart' show PubTopLevel, lineLength;
 import 'command/add.dart';
-import 'command/build.dart';
 import 'command/cache.dart';
 import 'command/deps.dart';
 import 'command/downgrade.dart';
@@ -23,7 +22,6 @@
 import 'command/outdated.dart';
 import 'command/remove.dart';
 import 'command/run.dart';
-import 'command/serve.dart';
 import 'command/token.dart';
 import 'command/upgrade.dart';
 import 'command/uploader.dart';
@@ -139,7 +137,6 @@
     // When adding new commands be sure to also add them to
     // `pub_embeddable_command.dart`.
     addCommand(AddCommand());
-    addCommand(BuildCommand());
     addCommand(CacheCommand());
     addCommand(DepsCommand());
     addCommand(DowngradeCommand());
@@ -149,7 +146,6 @@
     addCommand(OutdatedCommand());
     addCommand(RemoveCommand());
     addCommand(RunCommand());
-    addCommand(ServeCommand());
     addCommand(UpgradeCommand());
     addCommand(UploaderCommand());
     addCommand(LoginCommand());
diff --git a/lib/src/pub_embeddable_command.dart b/lib/src/pub_embeddable_command.dart
index 29ac73f..48c4258 100644
--- a/lib/src/pub_embeddable_command.dart
+++ b/lib/src/pub_embeddable_command.dart
@@ -8,7 +8,6 @@
 import 'command.dart' show PubCommand, PubTopLevel;
 import 'command.dart';
 import 'command/add.dart';
-import 'command/build.dart';
 import 'command/cache.dart';
 import 'command/deps.dart';
 import 'command/downgrade.dart';
@@ -90,7 +89,6 @@
     //
     // New commands should (most likely) be included in both lists.
     addSubcommand(AddCommand());
-    addSubcommand(BuildCommand());
     addSubcommand(CacheCommand());
     addSubcommand(DepsCommand());
     addSubcommand(DowngradeCommand());