Add stop method to stop the heartbeat checker when disconnected (#307)
Add stop method to stop the heartbeat checker when disconnected (#307)

vrtsystems/pika,jstnlef/pika,hugoxia/pika,Zephor5/pika,shinji-s/pika,vitaly-krugl/pika,pika/pika,reddec/pika,Tarsbot/pika,zixiliuyue/pika,skftn/pika,knowsis/pika,fkarb/pika-python3,benjamin9999/pika,renshawbay/pika-python3