update cran comments

Author: clauswilke

Diff for: cran-comments.md

@@ -9,7 +9,7 @@ Answer: No, no such reference exists at this time. I only have the code on githu
 
 ## Test environments
 * R devel and R 3.4.1 on win-builder [ via devtools::build_win() ]
-* local OS X install x86_64-apple-darwin13.4.0 (64-bit), R 3.3.1
+* local OS X install x86_64-apple-darwin15.6.0 (64-bit), R 3.4.1
 
 ## R CMD check results
 There were no ERRORs or WARNINGs.