codesniffer 3.4 support

[sergeynezbritskiy]

Preconditions

Together with this coding standard I'm trying to use this coding standard https://github.com/slevomat/coding-standard for checking php7 features.
Unfortunatelly this library requires codesniffer ^3.4.2, but magento coding standard requires codesnifer ~3.3.0 which means less the 3.4.0.

What about supporting Codesniffer 3.4 ?

[lenaorobei]

Hi @sergeynezbritskiy that's definitely in our roadmap and there should be no issues with that. I added this issue to the community dashboard. You are vey welcome to open PR with version upgrade if you are interested in taking care of it.

One thing we need to take into account is magento dependency update as well.
https://github.com/magento/magento2/blob/2.3-develop/composer.json#L94

[lenaorobei]

Fixed in #85
Thank you @sergeynezbritskiy!

[cmuench]

This change is good. But please keep an eye on backwards compatibility. We added the package via composer in our gitlab-ci pipeline. Every module which checks agains the latest Magento 2.3.1 is now broken.