Release rvest 1.0.0

[hadley]

Prepare for release:

• [x] devtools::build_readme()
• [x] Check current CRAN check results
• [x] devtools::check(remote = TRUE, manual = TRUE)
• [x] devtools::check_win_devel()
• [x] revdepcheck::cloud_check()
  • [x] coalitions — https://github.com/adibender/coalitions/pull/132
  • [x] fitzRoy — https://github.com/jimmyday12/fitzRoy/pull/137
  • [x] gluedown — https://github.com/kiernann/gluedown/pull/27
  • [x] helminthR — https://github.com/ropensci/helminthR/pull/23
  • [x] rMorningStar (figure out why type.convert now getting activated) — not on github
  • [x] rUnemploymentData — https://github.com/arilamstein/rUnemploymentData/pull/1
  • [x] ralger — https://github.com/feddelegrand7/ralger/pull/8
• [x] urlchecker::url_check()
• [x] Polish NEWS
• [x] Review pkgdown reference index for, e.g., missing topics
• [x] Draft blog post
• [x] Wait until March 1
• [x] Update cran-comments.md

Submit to CRAN:

• [x] usethis::use_version('major')
• [x] devtools::submit_cran()
• [x] Approve email
• [x] Patch for mitre: https://github.com/motherhack3r/mitre/pull/2

Wait for CRAN...

• [x] Accepted :tada:
• [x] usethis::use_github_release()
• [x] usethis::use_dev_version()
• [x] Finish blog post
• [x] Tweet
• [x] Add link to blog post in pkgdown news menu