Steps to publish a new Clippy version

• Bump package.version in ./Cargo.toml (no need to manually bump dependencies.clippy_lints.version).
• Write a changelog entry.
• Run ./pre_publish.sh
• Review and commit all changed files
• git push
• Wait for Travis's approval.
• Merge.
• cargo publish in ./clippy_lints.
• cargo publish in the root directory.
• git pull.
• git tag -s v0.0.X -m "v0.0.X".
• git push --tags.