Fix the bug that rabbit doesn't delete instance's logs when unprovision

Change-Id: I0be8277fc4e5e94c2b29c88144b6d3734664ee09

rabbit/lib/rabbit_service/rabbit_node.rb

@@ -372,7 +372,7 @@ def start_instance(instance)
 
       dir = instance_dir(instance.name)
       config_dir = File.join(dir, "config")
-      log_dir = File.join(@rabbitmq_log_dir, instance.name)
+      log_dir = instance_log_dir(instance.name)
       FileUtils.mkdir_p(config_dir)
       FileUtils.mkdir_p(log_dir)
       admin_port = instance.admin_port
@@ -451,6 +451,7 @@ def stop_instance(instance)
     instance.kill
     EM.defer do
       FileUtils.rm_rf(instance_dir(instance.name))
+      FileUtils.rm_rf(instance_log_dir(instance.name))
     end
   end
 
@@ -532,4 +533,7 @@ def instance_dir(instance_id)
     File.join(@base_dir, instance_id)
   end
 
+  def instance_log_dir(instance_id)
+    File.join(@rabbitmq_log_dir, instance_id)
+  end
 end