Fix analyzer hints and warnings in test/.

test/global/binstubs/removes_when_deactivated_test.dart

 // Copyright (c) 2014, 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 'package:scheduled_test/scheduled_test.dart';
-
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
-import 'utils.dart';
 
 main() {
   integration("removes binstubs when the package is deactivated", () {
     servePackages((builder) {
       builder.serve("foo", "1.0.0", pubspec: {
         "executables": {
           "one": null,
           "two": null
         }
       }, contents: [
         d.dir("bin", [
           d.file("one.dart", "main(args) => print('one');"),
           d.file("two.dart", "main(args) => print('two');")
         ])
       ]);
     });
 
     schedulePub(args: ["global", "activate", "foo"]);
     schedulePub(args: ["global", "deactivate", "foo"]);
 
     d.dir(cachePath, [
       d.dir("bin", [
         d.nothing(binStubName("one")),
         d.nothing(binStubName("two"))
       ])
     ]).validate();
   });
 }