Update cran-comments

Author: Paul Hoffman

cran-comments.md

@@ -3,6 +3,7 @@
 ## Test environments
 * local Ubuntu 16.04 and 18.04 installs, R 3.4.4
 * Ubuntu 12.04 (on travis-ci), R 3.5.0
+* macOS 10.12.6 (on travis-ci), R 3.5.0
 * win-builder (devel, release)
 
 ## R CMD check results
@@ -16,12 +17,9 @@ There were 2 NOTEs:
     loomR
   Availability using Additional_repositories specification:
     loomR   yes   https://mojaveazure.github.io/loomR
-  Uses the superseded package: 'doSNOW'
 
   The package we suggest, loomR, is currently underdevelopment and not yet available on CRAN. This package is not required for core functionality of Seurat.
 
-  We use doSNOW instead of doParallel because doSNOW has support for a progress bar while doParallel does not. doSNOW is still on CRAN and works for our purposes.
-
 * checking package dependencies ... NOTE
   Package suggested but not available for checking: 'loomR'