Release checklist

1. (optional) Bump the tcod-sys version in tcod_sys/Cargo.toml following http://semver.org/
2. (optional) Publish tcod-sys to crates.io if we have a new version:
   • cd tcod_sys && cargo package && ls -alh target/package/
   • cargo publish
   • Check the tcod-sys crates.io page
3. Bump the tcod version following http://semver.org/
4. Bump the tcod version in the How to use this part of the README, too!
5. Verify everything builds fine:
   • cargo build
   • cargo build --release
   • cargo build --examples
   • cargo test
6. git commit -m "Bump tcod to $version"
7. Create a pull request for the version bump commit
   • Verify the CI passes
   • Merge it
8. Run make package
9. Check that target/package/tcod-$version appears sane (e.g. it's not taking up 20MB)
10. Create a tag for the new version: git tag -a -m "Release version v${VERSION}" v$VERSION (e.g. git tag v3.4.6)
11. Push the tag: git push --follow-tags
12. Run cargo publish
13. Add the release notes:
    • Go to: https://github.com/tomassedovic/tcod-rs/releases
    • Click the Draft a new release button
    • Select the new tag from the Tag version dropdown
    • Write the version (without the v prefix, e.g. 3.4.6) as the Release title
    • Look through the new commits in this release and write a summary in the release notes section