Bug fix: Now handles that "summary" does not require any arguments.

tools/gardening/bin/summary.dart

Index: tools/gardening/bin/summary.dart
diff --git a/tools/gardening/bin/summary.dart b/tools/gardening/bin/summary.dart
index ac4d9b063b104986659a8d37e8c32c3e6647dbde..6febcddb8dad3b2a78e9aa7db6ef7fd4a1541121 100644
--- a/tools/gardening/bin/summary.dart
+++ b/tools/gardening/bin/summary.dart
@@ -17,10 +17,9 @@ main(List<String> args) async {
   ArgParser argParser = createArgParser();
   ArgResults argResults = argParser.parse(args);
   processArgResults(argResults);
-  if (argResults.rest.length == 0 || argResults['help']) {
+  if (argResults['help']) {
     help(argParser);
-    if (argResults['help']) return;
-    exit(1);
+    return;
   }
 
   var bot = new Bot(logdog: argResults['logdog']);