Remove pub tests for non-semantic SDK versions

dart/sdk/lib/_internal/pub/test/sdk_test.dart

-// 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 pub_tests;
-
-import 'package:unittest/unittest.dart';
-
-import '../lib/src/sdk.dart' as sdk;
-import '../lib/src/version.dart';
-
-main() {
-  group("parseVersion()", () {
-    test("parses a release-style version", () {
-      expect(sdk.parseVersion("0.1.2.0_r17645"),
-          equals(new Version.parse("0.1.2+0.r17645")));
-    });
-
-    test("parses a dev-only style version", () {
-      // The "version" file generated on developer builds is a little funky and
-      // we need to make sure we don't choke on it.
-      expect(sdk.parseVersion("0.1.2.0_r16279_bobross"),
-          equals(new Version.parse("0.1.2+0.r16279.bobross")));
-    });
-  });
-}