message: added link to the BP heartbeat plugin
  Added link to the heartbeat plugin (details here: https://medium.com/@liquideos/increasing-stability-of-the-eos-blockchain-11921477549e)
  Some BPs have started using it (as can be seen here: http://heartbeat.liquideos.com/), So people in the community requested that i add it here as well.
  A curated list of some more plugins can be found here:
diff: @@ -10,6 +10,7 @@ Third parties are encouraged to make pull requests to this file (`develop` branc
  | Kafka | https://github.com/TP-Lab/kafka_plugin |
  | SQL | https://github.com/asiniscalchi/eosio_sql_plugin |
  | ElasticSearch | https://github.com/EOSLaoMao/elasticsearch_plugin |
  +| BP Heartbeat | https://github.com/bancorprotocol/eos-producer-heartbeat-plugin |
  ## DISCLAIMER:
  