[Rd] rchk on github

[Ben Bolker]

   I'm noticing that some CRAN infrastructure still seems to be hosted 
on Tomas Kalibera's github account, which will presumably go away at 
some point ...

https://github.com/kalibera/rchk

There are a few up-to-date forks lying around (just forked it myself), 
so I guess the content can be rescued even if this repo suddenly goes 
away ... ??

   A similar question goes for his dockerhub images: 
https://hub.docker.com/u/kalibera (maybe the rocker project would take 
those over ... ??)

   cheers
     Ben Bolker