Fix error in validation of datetime

Allow to install in PHP8 environment (#35)

Add build matrix capability (#32)

* Add workflow for possible future php versions

Co-authored-by: Sara Gfrörer <[email protected]>

22 datetime error (#24)

* [#22] Add PHP 7.4 for testing environment

* [#22] Add better type hints

Add vendor namespace

Add EnumType #19 (#20)

* Add EnumType #19
* Remove unsupported hhvm; Add php7.2; Update Readme.md

Add optional type (#17)

* Add optional type

Resolve #16

* Use php5 compatible version

Create count check (#15)

7 regex type (#13)

* Add datetime type

* Update type list in readme

* Add regex type

Add exact value type

This solves #6