Added purity markers for enumerables, improved type definitions#140

Merged

marc-mabe merged 3 commits intomarc-mabe:masterfrom Ocramius:feature/pure-enumerable

Apr 5, 2020

+342-80

Commits on Apr 2, 2020

Upgraded to phpunit/phpunit 7.x to allow sebastian/diff 3.x compatibility
Ocramius
committed
Added immutability/purity markers, refined psalm types, tested types
Ocramius
committed
Removed build/test sources/artifacts from exported released packages
Ocramius
committed