Add .gitlab-ci for continious integration

I have added gitlab ci please review it.
Thank!!

@chandansha thank you for contribution. I think we should also take the opportunity to fix the cspell, phpcs and phpstan warnings in this ticket.

Fixed phpcs/phpstan/cspell issues. Cspell still reports some findings, but this is a variable names and string literates. I think we should ignore it

Looks good, will merge.

Automatically closed - issue fixed for 2 weeks with no activity.