Add a LiveSuite class.

test/io.dart

Index: test/io.dart
diff --git a/test/io.dart b/test/io.dart
index f7ead650692c26604599182f08e457ca574c7e79..00bb3e0c12bf801fd3ab5a5e59ad6babd7bbf560 100644
--- a/test/io.dart
+++ b/test/io.dart
@@ -7,6 +7,7 @@
 library test.test.io;
 
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
 
 import 'package:path/path.dart' as p;
@@ -15,6 +16,7 @@ import 'package:scheduled_test/scheduled_process.dart';
 import 'package:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 import 'package:test/src/util/io.dart';
+import 'package:yaml/yaml.dart';
 
 /// The path to the root directory of the `test` package.
 final String packageDir = p.dirname(p.dirname(libraryPath(#test.test.io)));