Remove deprecated StringBuffer.add, addAll and addCharCode.

pkg/scheduled_test/lib/src/descriptor/utils.dart

Index: pkg/scheduled_test/lib/src/descriptor/utils.dart
diff --git a/pkg/scheduled_test/lib/src/descriptor/utils.dart b/pkg/scheduled_test/lib/src/descriptor/utils.dart
index c6490195c91011d3f7a75fec0c0bb953ebb24498..30d809ee820e4677efc2ae75daef83e1d8e5c54f 100644
--- a/pkg/scheduled_test/lib/src/descriptor/utils.dart
+++ b/pkg/scheduled_test/lib/src/descriptor/utils.dart
@@ -48,7 +48,7 @@ String describePattern(Pattern pattern) {
   if (pattern is! RegExp) return '$pattern';
 
   var flags = new StringBuffer();
-  if (!pattern.isCaseSensitive) flags.add('i');
-  if (pattern.isMultiLine) flags.add('m');
+  if (!pattern.isCaseSensitive) flags.write('i');
+  if (pattern.isMultiLine) flags.write('m');
   return '/${pattern.pattern}/$flags';
 }