Release checklist

• all pending pull requests are merged
• eslint is satisfied (yarn eslint)
• there are no orphaned files, the repository is clean
• checkout the related stable branch (e.g. stable2)
• merge dev branch (git merge dev)
• bump version in package.json according to semantic versioning
• create commit (git commit -am "bump version to vX.X.X")
• create tag (git tag -a vX.X.X -m "tag vX.X.X")
• build css files by calling gulp sass
• make sure submodules are up to date (git submodule update --init)
• pack build by calling node scripts/pack-build.js
• push commit and tag (git push origin && git push origin --tags)
• update changelog in wiki
• create release from tag on Github and attach archives (zip and tar)
• party 🎉