Fix Dart 1.17 strong-mode warnings.

test/typed_wrapper/stream_test.dart

Index: test/typed_wrapper/stream_test.dart
diff --git a/test/typed_wrapper/stream_test.dart b/test/typed_wrapper/stream_test.dart
index 4936120f025a3b65d9b6b05f2b6433b9ecf4a2a2..05cde3a93e7a8ae572bbdf0b3a8795fc857f7662 100644
--- a/test/typed_wrapper/stream_test.dart
+++ b/test/typed_wrapper/stream_test.dart
@@ -4,7 +4,6 @@
 
 import 'dart:async';
 
-import "package:async/async.dart";
 import "package:async/src/typed/stream.dart";
 import "package:test/test.dart";
 
@@ -245,7 +244,7 @@ void main() {
     });
 
     test("pipe()", () {
-      var consumer = new StreamController<T>();
+      var consumer = new StreamController();
       expect(wrapper.pipe(consumer), completes);
       expect(consumer.stream.toList(), completion(equals([1, 2, 3, 4, 5])));
     });