Delete a bunch of packages that are now on GitHub.

pkg/oauth2/lib/src/expiration_exception.dart

Index: pkg/oauth2/lib/src/expiration_exception.dart
diff --git a/pkg/oauth2/lib/src/expiration_exception.dart b/pkg/oauth2/lib/src/expiration_exception.dart
deleted file mode 100644
index 9829de1e13017a6252aea4f8ad3e8084594954f4..0000000000000000000000000000000000000000
--- a/pkg/oauth2/lib/src/expiration_exception.dart
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright (c) 2012, 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 expiration_exception;
-
-import 'credentials.dart';
-
-/// An exception raised when attempting to use expired OAuth2 credentials.
-class ExpirationException implements Exception {
-  /// The expired credentials.
-  final Credentials credentials;
-
-  /// Creates an ExpirationException.
-  ExpirationException(this.credentials);
-
-  /// Provides a string description of the ExpirationException.
-  String toString() =>
-    "OAuth2 credentials have expired and can't be refreshed.";
-}