Update cran comments

Author: hadley

cran-comments.md

@@ -4,4 +4,24 @@ There were no ERRORs, WARNINGs, or NOTEs.
 
 ## revdepcheck results
 
-I did not check any revdeps, since the changes are minimal and should only affect interactive usage.
+We checked 7097 reverse dependencies (7083 from CRAN + 14 from Bioconductor), comparing R CMD check results across CRAN and dev versions of this package. We failed to check 17 packages (listed below) but did not otherwise see any problems.
+
+### Failed to check
+
+* Boom         (NA)
+* CausalImpact (NA)
+* ctsem        (NA)
+* elbird       (NA)
+* ggPMX        (NA)
+* loon.ggplot  (NA)
+* loon.shiny   (NA)
+* loon.tourr   (NA)
+* mlrCPO       (NA)
+* nlmixr2      (NA)
+* nlmixr2extra (NA)
+* nlmixr2plot  (NA)
+* OpenMx       (NA)
+* rPBK         (NA)
+* SSVS         (NA)
+* tidySEM      (NA)
+* vivid        (NA)