Tidyup flutter_analyzer_server_test (#586)

diff --git a/pubspec.lock b/pubspec.lock
index 989e3dd..484128c 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -609,7 +609,7 @@
       name: uuid
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.2.0"
+    version: "2.2.2"
   vm_service:
     dependency: transitive
     description:
diff --git a/test/flutter_analysis_server_test.dart b/test/flutter_analysis_server_test.dart
index 17b5d04..28cfb4a 100644
--- a/test/flutter_analysis_server_test.dart
+++ b/test/flutter_analysis_server_test.dart
@@ -204,14 +204,17 @@
   group('Flutter SDK analysis_server', () {
     setUp(() async {
       flutterWebManager = FlutterWebManager(SdkManager.flutterSdk);
-      await flutterWebManager.initFlutterWeb();
+      await flutterWebManager.warmup();
       analysisServer = AnalysisServerWrapper(
           SdkManager.flutterSdk.sdkPath, flutterWebManager);
       await analysisServer.init();
       await analysisServer.warmup();
     });
 
-    tearDown(() => analysisServer.shutdown());
+    tearDown(() async {
+      await analysisServer.shutdown();
+      await flutterWebManager.dispose();
+    });
 
     test('analyze counter app', () async {
       final results = await analysisServer.analyze(counter);