Further automate pre_publish.sh

[phansch]

The script now runs the tests after cargo fmt.

[Manishearth]

Are we running this at all now given that we distribute clippy with rustc?

I was going to suggest replacing the published clippy with a no-op crate that tells you to install clippy the real way via a build script

[phansch]

If we don't release versions or publish git tags anymore, we can change the commit message in this script and remove a few replacements from util/update_lints.py. Apart from that, I think we can continue to use the script in one form or another. It does a lot of things currently:

0. Some git diffing, which I don't really understand the purpose of
1. Calls util/update_lints.py which should be used when adding new lints, but sometimes is forgotten/done manually. Running this during publishing just makes sure that the lint counter in the README is correct and that the changelog links are correct. The script..
   1. Updates the lint counter in the README
   2. Updates the hidden changelog lint links at the bottom
   3. Sets the clippy_lints version in Cargo.toml to the clippy version
   4. Inserts missing pub mod lint_name in clippy_lints/src/lib.rs
   5. Adds missing lints to the respective lint groups in clippy_lints/src/lib.rs
2. It creates a "Bump the version" commit with the above changes
3. It runs rustfmt
4. It tells the user a few more manual things to do in preparation for publishing a new release

[oli-obk]

The diffing was to ensure that you didn't forget to actually bump the verison or edit the CHANGELOG.

Just remove all that nonsense now ;)

[phansch]

Removed the git diffing part