Testing tools installed and managed by https://github.com/bamarni/composer-bin-plugin.

Note that this should only be used for tools that are self-contained (specifically, not phpunit).

To add a tool:

• composer bin <tool-name> require --dev <package>
• cd tools
• ln -s ../vendor-bin/<tool-name>/vendor/bin/<tool-executable>

Tools are automatically updated as part of composer update.