Add summary command to bot.

tools/gardening/bin/bot.dart

Index: tools/gardening/bin/bot.dart
diff --git a/tools/gardening/bin/bot.dart b/tools/gardening/bin/bot.dart
index 2226637700bf1daad5b00cfe61a302a6bccfc5b4..75c29009cb0562fd01e3f352b2402e691a924fdc 100644
--- a/tools/gardening/bin/bot.dart
+++ b/tools/gardening/bin/bot.dart
@@ -7,8 +7,9 @@ import 'dart:io';
 
 import 'compare_failures.dart' as compare_failures;
 import 'current_summary.dart' as current_summary;
-import 'status_summary.dart' as status_summary;
 import 'find_shard.dart' as find_shard;
+import 'status_summary.dart' as status_summary;
+import 'summary.dart' as summary;
 
 typedef Future MainFunction(List<String> args);
 
@@ -30,6 +31,7 @@ help(List<String> args) async {
 
 const Map<String, MainFunction> commands = const <String, MainFunction>{
   "help": help,
+  "summary": summary.main,
   "compare-failures": compare_failures.main,
   "current-summary": current_summary.main,
   "status-summary": status_summary.main,