php-code-sniffs
Use squizlabs/php_codesniffer to check your code style.
Remove some coding standards, and add a few more.
Installation
You can install phpcs with this 2 methods:
Code sniffs
List of enabled code sniffs is available here.
You can configure some of them with a bootstrap file.
Run phpcs with CircleCI
And example of how to use Docker image with CircleCI is available here.