update NEWS and cran comments

NEWS.md

@@ -1,3 +1,7 @@
+## rncl 0.8.4
+
+* Maintenance release that fixes warnings on CRAN checks.
+
 ## rncl 0.8.3
 
 * Maintenance release that fixes notes and warnings from CRAN checks.

cran-comments.md

@@ -1,20 +1,26 @@
 ## Test environments
 
-- local Ubuntu 18.04, R 3.5.1
-- Ubuntu 14.04 (travis-ci), R 3.5.0
-- Windows with win-builder using R release (3.5.1) and R-devel r
+- local Ubuntu 18.10, R 3.6.2
+- Ubuntu 16.04 (travis-ci), R 3.6.2
+- Windows with win-builder using R release (3.6.2) and R-devel
+- Ubuntu 18.04 - R Under development (unstable) (2020-02-08 r77786)
 - Debian testing with R-devel (2018-07-14 r74963)
 
 ## Notes
 
-- This release fixes the NOTEs on the CRAN check results page about registering
-  native routines and disabling symbol search
-- It also addresses a warning detected by the upcoming relase of clang 7 brought
-  up by Prof Brian Ripley in an email sent to me on 2018-07-27
+- This release fixes the WARNINGS on the CRAN check results page.
 
 ## R CMD check results
 
 - There were no errors or warnings.
+- There is a NOTE about a possibly invalid URL but the link works:
+
+   Found the following (possibly) invalid URLs:
+     URL: https://doi.org/10.1093/sysbio/46.4.590
+       From: man/rncl.Rd
+       Status: Error
+       Message: libcurl error code 56:
+         	Recv failure: Connection was reset
 
 ## Downstream dependencies