tools-init.sh will install vip-go-ci, PHPCS and related tools in your home-directory upon execution. If the tools are already installed, it will update them as needed; it should be executed on regular basis to keep everything up to date. See installation section.
However, once a while tools-init.sh itself needs to be updated with new versions of these utilities. The file keeps three data entries for each utility that are important in this context: Repository owner and name for the utility, version number, and SHA1 hash. The repository owner and name refers to the GitHub repository where the utility is hosted, the version number refers to a release number on GitHub, and the hash to the SHA1 hash of the release's .tar.gz archive on GitHub. The hash is used to make sure that the relevant utility has not changed since last updated in tools-init.sh.
Only version number and SHA1 hash need updating for a new release of a utility. These can be determined in the following way. Releases of the WordPress-Coding-Standards utility, for instance, are hosted here. Once a version has been chosen, tools-init.sh can be updated in the following way:
export WP_CODING_STANDARDS_VER="2.1.1"
Then the hash has to be calculated. First, obtain a .tar.gz archive for the release from GitHub. The download URL for WordPress-Coding-Standards is: https://github.com/WordPress/WordPress-Coding-Standards/archive/VERSION.tar.gz — simply replace VERSION with the version to be used. Then run the sha1sum UNIX utility against the downloaded file. Any other compatible tool can be used.
For version 2.1.1 of WordPress-Coding-Standards the hash should be specified as follows:
export WP_CODING_STANDARDS_SHA1SUM="d35ec268531453cbf2078c57356e38c5f8936e87";
All utilities in tools-init.sh follow the same pattern. Utility updates in the file should be committed to the repository via pull requests.