Checklist for CRAN release

The following items (written down during the lead-up to the 1.0-5 CRAN release) should be checked by the main release developer (DK, presently) as the steps are done. Once a CRAN release is made, they should all be unchecked.

1. If the netcdf file supplied by GSW-Fortran has changed, rebuild the SAAR database by visiting the developer/create_data directory, typing make clean to reset, then make to build a local rda file and then -- if you trust that rda file -- make install.
2. Examine DESCRIPTION and NEWS carefully. In DESCRIPTION, is the version number higher than that on CRAN, and is the the same as today's date? In NEWS, are new items listed in NEWS?
3. Examine cran-comments.md and think about whether things need to be updated (e.g. NUMBER of packages). IMPORTANT it's not clear to DK whether we are meant to alter this file, or whether devtools::release is meant to do that.
4. build and check locally
5. rebuild and recheck oce and ocedata locally
6. rhub::check()
7. rhub::check_for_cran() ... NOTE. 1.0-5 has a problem on some of the test machines, in finding a .svg file from travis-ci. However, other machines report no problem, and the file can be downloaded with curl, so I am going to ignore this. (It's in checking the README.md file with pandoc, and a web search shows problems with this for other projects. Plus, the README.md looks fine on github, which is all that matters.)
8. devtools::build_win(version="R-release")
9. devtools::build_win(version="R-devel")
10. Think about all of the above. Be sure that no steps give errors. If there are warnings or notes, try to find a way to solve them, and start over from step 1. Give yourself time to decide if you really want to do a release. CRAN is not happy to get frequent updates, but if they say "ASAP", get a wiggle on.
11. Release using devtools::release. Note that this does a lot of testing and evaluation. You'll need to set aside an hour at the computer, to go through the steps.