[v2.0.2] dependency and documentation updates

[misc] regenerate toc

[v2.0.1] support queue maxsize of -1

[2.0.1] bump to 2.0.1

[v2.0.0] add php 8 support and drop php < 7.4

[docs] update README.md for travis-ci.com

v1.2.0

[1.2.0] bump to 1.2.0

v1.0.2

updated README.md coverage badge

v1.0.1

[1.0.1] update README.md

v1.0.0

[1.0.0] misc refactoring

v0.2.1

[v0.2.1] fix composer.json version

v0.2.0

bump to 0.2.0