update CRAN comments

Author: timelyportfolio

cran-comments.md

@@ -1,6 +1,5 @@
 ## Test environments
-* local Windows 10 install, R 3.3.1
-* ubuntu 12.04 (on travis-ci), R 3.3.1
+* local Windows 10 install, R 3.4.0
 * rhub check_for_cran
 
 ## R CMD check results
@@ -18,4 +17,4 @@ File 'LICENSE':
 
 ## Reverse dependencies
 
-This is a new release, so there are no reverse dependencies.
+There are no reverse dependencies.