Update README.md

v.2.8.1 accepted on CRAN

fixed error on submission report

2.1.6 first release attempt - fixed spatstat

tag for release

Merge pull request #50 from AndrewLJackson/try-remove-NOTEs

removed dplyr NOTEs

prerelease push: no errors or warnings or notes

doc updates

submitted to CRAN

had to add a note to deal with an error thrown by remote checking on an
old release that seems to lack an appropriate JAGS installation

cran-comments updated and vignettes rebuilt