CRAN release version 1.3.1

Documentation

[x] Vignettes have been updated by opening the vignettes/precompile.R file and running the script
[x] Documentation has been built with roxygen::roxygenise()
[x] _pkgdown.yml has been updated with any new/updated changes
[x] pkgdown site has been built locally with pkgdown::build_site() and all the pages are rendering as expected
[x] NEWS.md has been updated with all the changes since the last release, including links to issue numbers
[x] Version number has been increased in the DESCRIPTION in semantic versioning style

[x] Delete all files from the tests/fixtures/ folder
[x] All automated tests are passing locally with devtools::test() (including slow skipped tests)
[x] All functional tests documented here have been performed, ideally by someone other than the developer
[x] Code has been merged into the master branch and pushed to Git (including re-generated fixtures)
[x] Tests are passing on the master branch on travis

[x] R CMD build galah and R CMD check --as-cran --no-manual galah_{version}.tar.gz run with no issues
[x] Package checked using rhub::check_for_cran()
[x] rhub results (emailed to maintainer) have no errors or warnings
[x] Package zipfile has been submitted to winbuilder
[x] winbuilder results (emailed to maintainer) have no errors or warnings