Remove unused option in server API

pkg/analysis_server/test/source/test_all.dart

Index: pkg/analysis_server/test/source/test_all.dart
diff --git a/pkg/analysis_server/test/source/test_all.dart b/pkg/analysis_server/test/source/test_all.dart
deleted file mode 100644
index 1389dd310eb035123bee581fa0d62e75decd2766..0000000000000000000000000000000000000000
--- a/pkg/analysis_server/test/source/test_all.dart
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright (c) 2015, 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 test.source;
-
-import '../utils.dart';
-import 'caching_put_package_map_provider_test.dart' as caching_provider_test;
-
-/// Utility for manually running all tests.
-main() {
-  initializeTestEnvironment();
-  caching_provider_test.main();
-}