Move pub into sdk/lib/_internal.

utils/tests/pub/install/hosted/resolve_constraints_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 'dart:io';
-
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-  integration('resolves version constraints from a pub server', () {
-    servePackages([
-      packageMap("foo", "1.2.3", [dependencyMap("baz", ">=2.0.0")]),
-      packageMap("bar", "2.3.4", [dependencyMap("baz", "<3.0.0")]),
-      packageMap("baz", "2.0.3"),
-      packageMap("baz", "2.0.4"),
-      packageMap("baz", "3.0.1")
-    ]);
-
-    d.appDir([dependencyMap("foo"), dependencyMap("bar")]).create();
-
-    schedulePub(args: ['install'],
-        output: new RegExp("Dependencies installed!\$"));
-
-    d.cacheDir({
-      "foo": "1.2.3",
-      "bar": "2.3.4",
-      "baz": "2.0.4"
-    }).validate();
-
-    d.packagesDir({
-      "foo": "1.2.3",
-      "bar": "2.3.4",
-      "baz": "2.0.4"
-    }).validate();
-  });
-}