If growlnotify not available, output with puts.

This allows using watchr to run the tests on e.g. Linux.

test.watchr

@@ -3,10 +3,14 @@ system 'clear'
 
 def growl(message)
   growlnotify = `which growlnotify`.chomp
-  title = "Watchr Test Results"
-  image = message.include?('0 failures, 0 errors') ? "~/.watchr_images/passed.png" : "~/.watchr_images/failed.png"
-  options = "-w -n Watchr --image '#{File.expand_path(image)}' -m '#{message}' '#{title}'"
-  system %(#{growlnotify} #{options} &)
+  if not growlnotify.empty?
+    title = "Watchr Test Results"
+    image = message.include?('0 failures, 0 errors') ? "~/.watchr_images/passed.png" : "~/.watchr_images/failed.png"
+    options = "-w -n Watchr --image '#{File.expand_path(image)}' -m '#{message}' '#{title}'"
+    system %(#{growlnotify} #{options} &)
+  else
+    puts message
+  end
 end
 
 def run(cmd)
@@ -67,4 +71,4 @@ Signal.trap 'INT' do
     # raise Interrupt, nil # let the run loop catch it
     run_suite
   end
-end
+end