Explanation for binary files inside source package according to
  https://lists.debian.org/debian-devel/2013/09/msg00332.html

Files: tests/testthat/*/data/a.rda
Documented: Stored test data to compare test results

 -- Andreas Tille <tille@debian.org>  Wed, 09 May 2018 20:48:49 +0200
