Commit d6bd82865c removed apigen from
WooCommerce core repository as we are moving it to its own repository (https://github.com/woocommerce/woocommerce-api-docs). This
commit removes the apigen from configuration files. In most cases, it is
just removing the apigen directory from the exclude list of things like
PHPCS and Code Climate.
This commit renames PHPCS configutarion file to `phpcs.xml`. With the default name, it is not necessary to use the argument `--standard=phpcs.ruleset.xml` anymore when calling `phpcs`.
Claudio Sanches
Rodrigo Primo