Fix analyzer hints and warnings in test/.

test/global/binstubs/does_not_warn_if_no_executables_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 'dart:io';
-
-import 'package:path/path.dart' as p;
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   integration("does not warn if the package has no executables", () {
     servePackages((builder) {
       builder.serve("foo", "1.0.0", contents: [
         d.dir("bin", [
           d.file("script.dart", "main(args) => print('ok \$args');")
         ])
       ]);
     });
 
     schedulePub(args: ["global", "activate", "foo"],
         output: isNot(contains("is not on your path")));
   });
 }