Removed fixed dependencies

packages/crypto/lib/crypto.dart

Index: packages/crypto/lib/crypto.dart
diff --git a/packages/crypto/lib/crypto.dart b/packages/crypto/lib/crypto.dart
new file mode 100644
index 0000000000000000000000000000000000000000..990349a4698d56a7e5fa00af8277a180ed0972fc
--- /dev/null
+++ b/packages/crypto/lib/crypto.dart
@@ -0,0 +1,10 @@
+// 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.
+
+export 'src/digest.dart';
+export 'src/hash.dart';
+export 'src/hmac.dart';
+export 'src/md5.dart';
+export 'src/sha1.dart';
+export 'src/sha256.dart';