Announcing secr 3.1.8 and openCR 1.3.0

For the record, there are new versions of secr and openCR on CRAN. Overview at https://www.otago.ac.nz/density/News.html and details at https://CRAN.R-project.org/package=secr and https://CRAN.R-project.org/package=openCR.