Fix github issue #5:

Ensure that entries in internal queue of logstash have been sent before
monasca log-agent stops.

Author: mattibf

lib/logstash/outputs/monasca_log_api.rb

@@ -208,6 +208,10 @@ def start_time_check
   end
 
   def stop_time_check
+    #ensure that entries buffered in queue will be  handled before stop
+    @mutex.synchronize do
+      send_logs
+    end
     @time_thread.kill() if @time_thread
     @logger.info('Stopped time_check thread')
   end