[easybuild] sanity check for R

[John Dey]

I have never seen a sanity check failure for R extensions until upgrading
to EB 3.6.2.  I now have 53 failures.  How is EB testing sanity? Many of
these packages output citation information, copyright notices, brief
tutorials, etc... when loaded with library command.

John Dey
j...@fuzzdog.com