Update to R RNG causes errors

[jknowles]

See the errors here:

https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-clang/eeptools-00check.html

From Kurt @ CRAN:

The previous method can be requested using RNGkind() or RNGversion() if necessary for reproduction of old results.

To make your package successfully pass the checks for current R-devel and R-release you may find it most convenient to insert

suppressWarnings(RNGversion("3.5.0"))

before calling set.seed() in your example, vignette and test code (where the difference in RNG sample kinds matters, of course).