Fix analyzer_experimental hints: remove unused imports.

pkg/analyzer_experimental/test/options_test.dart

 // Copyright (c) 2013, 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 options_test;
 
 import 'package:unittest/unittest.dart';
-import 'package:analyzer_experimental/options.dart';
+//import 'package:analyzer_experimental/options.dart';
 
 main() {
 
   group('AnalyzerOptions.parse()', () {
 
     test('defaults', () {
 //      CommandLineOptions options = CommandLineOptions.parse(['foo.dart']);
 //      expect(options, isNotNull);
 //      expect(options.shouldBatch, isFalse);
 //      expect(options.machineFormat, isFalse);
@@ skipping 15 matching lines @@
 //      CommandLineOptions options = new CommandLineOptions.parse([
 //        '--ignore_unrecognized_flags', '--bar', '--baz', 'foo.dart']);
 //      expect(options, isNotNull);
 //      expect(options.sourceFiles, equals(['foo.dart']));
 //    });
 
   });
 
 }