rlang support

rlang support!

https://index.docker.io/u/chilijung/docker-r/
passing trust build in index.docker.io
I always use this

    sudo apt-add-repository -y "deb http://cran.rstudio.com/bin/linux/ubuntu `lsb_release -cs`/"

for reasons

1. you do not directly touch sources.list
2. the RStudio cloud mirror should be faster on average
3. Ubuntu version not hard-coded

Anyway, it is pretty cool to see R supported (?) in Drone, but why is it not listed in the documentation? http://docs.drone.io