mongoose release procedure

1. tests must pass
2. update package.json and package-lock.json version
3. update CHANGELOG.md. Add # as well as a link to the github user who fixed it if applicable.
4. git commit -a -m 'release x.x.x'
5. git tag x.x.x
6. npm run release, or npm run release-legacy for 4.x
7. update mongoosejs.com (see "updating the website" below)
8. tweet changelog link from @mongoosejs
9. Announce on mongoosejsteam slack channel
10. if this is a legacy release, git merge changes into master.

updating the website

For 6.x

1. Change to the master branch
2. execute npm run docs:prepare:publish:stable (when this process completes you'll be on the gh-pages branch)
3. git commit -a -m 'chore: website 6.x.x'
4. git push origin gh-pages

For 5.x

1. Change to the 5.x branch
2. execute make docs_legacy (when this process completes you'll be on the gh-pages branch)
3. git commit -a -m 'chore: website 5.x.x'
4. git push origin gh-pages