Test environments local OS X install, R 3.4.0 ubuntu 14.04.5 LTS (on travis-ci), R 3.4.2 rhub - Windows Server 2008 R2 SP1, R-devel, 32/64 bit, R 3.4.2 R CMD check results 0 errors | 0 warnings | 0 notes Reverse dependencies There are no reverse dependencies.