Resubmission

This is an update that replaces deprecated tidyr functions used in data processing.

There are no notes, warnings or errors from R CMD check.

Test environments

Ubuntu 14.04.5 (on Travis-CI): R devel and release
local MacOS 10.14.6 installation: R 3.6.1
win-builder (devel and release)

##R CMD check results 0 errors | 0 warnings | 0 notes