Allow PHP8 & Fix PHPUnit deprecations (thephpleague#146)

* Fix PHPUnit deprecations

* Allow PHP8

Symfony 5 support (thephpleague#133)

* Symfony 5 Support

* Fix vertex test

* Add idea folder to ignore

* Fix travis build

* remove idea from gitignore

Prepare for 0.8.0 (thephpleague#115)

* Prepare for 0.8.0

* Update CHANGELOG.md

prepare release 0.7.0

prepare release 0.6.0

prepare release 0.5.0

prepare release 0.3.3

prepare release 0.3.2

prepare release 0.3.1