Standard issue "template" for releasing a package

[hadley]

For now, this issue is just a place to dump ideas as they occur to me. No need to implement yet.

Prepare for release:

* [ ] `devtools::check_win_devel()`
* [ ] `rhub::check_for_cran()`
* [ ] `revdepcheck::revdep_check(num_workers = 4)`
* [ ] [Polish NEWS](http://style.tidyverse.org/news.html#before-release)
* [ ] If new failures, update `email.yml` then `revdepcheck::revdep_email_maintainers()`

Perform release:

* [ ] Create RC branch (for bigger releases)
* [ ] Bump version (in DESCRIPTION and NEWS)
* [ ] `devtools::check_win_devel()` (again!)
* [ ] `devtools::submit_cran()`
* [ ] `pkgdown::build_site()`
* [ ] Approve email

Wait for CRAN...

* [ ] Tag release
* [ ] Merge RC back to master branch
* [ ] Bump dev version
* [ ] Write blog post
* [ ] Tweet
* [ ] Add link to blog post in pkgdown news menu

Template from <https://github.com/r-lib/usethis/issues/338>

[hadley]

Maybe with variation for first release?

* [ ] Check that description is informative
* [ ] Check licensing of included files