Update revdep checks

Author: hadley

cran-comments.md

@@ -10,8 +10,8 @@ There were no ERRORs, WARNINGs or NOTEs.
 This release changes the backend of stringr from R's built in regular 
 expression engine to use instead use ICU's, as provided by the stringi
 package. The potential for backward incompatible changes was high so I have
-R CMD check on all 144 downstream dependencies 
+R CMD check on all 155 downstream dependencies 
 (https://github.com/hadley/stringr/blob/master/revdep/summary.md). As well
 as carefully reviewing the results, I notified all downstream maintainers
-of the pending change on Dec 5, giving them a month to check their package
-and make changes.
+of the pending change in early Dec, giving them a lot of time to check their 
+packages and make changes.