Release v0.8.4.
Release v0.8.4.

vish74/node-telegram-bot-api,SerjoPepper/node-telegram-bot-api,yagop/node-telegram-bot-api,palmerabollo/node-telegram-bot-api,alfcrisci/node-telegram-bot-api,MOSAVI17/Worldbot,tjhorner/node-telegram-bot-api,ioiasff/frt,codeRuth/node-telegram-bot-api,DarkScorpion/node-telegram-bot-api,rzr775/tryout-bot-not-functionally,yangit/node-telegram-bot-api