Show the help screen instead of an error when no arguments are given

git-svn-id: http://svn.rubyonrails.org/rails/tools/switchtower@2117 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Show the help screen instead of an error when no arguments are given
+
 * Make SwitchTower easier to invoke programmatically via SwitchTower::CLI
 
 * Specify the revision to release via the :revision variable (defaults to latest revision)

lib/switchtower/cli.rb

@@ -123,7 +123,12 @@ rake tasks in config/tasks, and a switchtower script in your script directory.
 (Currently, --apply-to only works with Rails applications.)
 DETAIL
 
-        opts.parse!(args)
+        if args.empty?
+          puts opts
+          exit
+        else
+          opts.parse!(args)
+        end
       end
 
       check_options!