fix analyzer warnings

Including using latest pkg/test expectAsync2 method

pkgs/stack_trace/pubspec.yaml

diff --git a/pkgs/stack_trace/pubspec.yaml b/pkgs/stack_trace/pubspec.yaml
index 850a701..93f059e 100644
--- a/pkgs/stack_trace/pubspec.yaml
+++ b/pkgs/stack_trace/pubspec.yaml
@@ -7,16 +7,14 @@
 #
 # When the major version is upgraded, you *must* update that version constraint
 # in pub to stay in sync with this.
-version: 1.7.3
+version: 1.7.4-dev
 author: "Dart Team <misc@dartlang.org>"
 homepage: https://github.com/dart-lang/stack_trace
-description: >
-  A package for manipulating stack traces and printing them readably.
-
+description: A package for manipulating stack traces and printing them readably.
 dependencies:
   path: "^1.2.0"
 
 dev_dependencies:
-  test: "^0.12.0"
+  test: '^0.12.17'
 environment:
   sdk: ">=1.14.0 <2.0.0"

pkgs/stack_trace/test/chain/chain_test.dart

diff --git a/pkgs/stack_trace/test/chain/chain_test.dart b/pkgs/stack_trace/test/chain/chain_test.dart
index 60137c8..b974aa9 100644
--- a/pkgs/stack_trace/test/chain/chain_test.dart
+++ b/pkgs/stack_trace/test/chain/chain_test.dart
@@ -8,7 +8,6 @@
 import 'package:stack_trace/stack_trace.dart';
 import 'package:test/test.dart';
 
-import '../utils.dart';
 import 'utils.dart';
 
 typedef void ChainErrorCallback(stack, Chain chain);
@@ -48,11 +47,10 @@
     test("with onError blocks errors", () {
       Chain.capture(() {
         return new Future.error("oh no");
-      }, onError: expectAsync((error, chain) {
+      }, onError: expectAsync2((error, chain) {
         expect(error, equals("oh no"));
         expect(chain, new isInstanceOf<Chain>());
-      }) as ChainErrorCallback, when: false);
-      // TODO(rnystrom): Remove this cast if expectAsync() gets a better type.
+      }), when: false);
     });
 
     test("doesn't enable chain-tracking", () {