The Rocket.Chat server was updated from 1.2 to 1.3.2.  This is the latest stable 1.x version.  2.0.0 was released days ago and will be implemented once it has been tried and tested.  Most likely we will wait until version 2.1.x is released to the wild.  If you want to know more please check out the official Rocket.Chat release notes.

https://github.com/RocketChat/Rocket.Chat/releases