Merge pull request #19 from zefrof/return-types

correct return types for getPid and getResultType

updated tests to work with php8 and phpunit11 and fixed a bug

Update README.md

added php 7.4 and php 8 support

Merge pull request #15 from HongjiangHuang/master

fix: recive ctrl+c signal kill  child process

dropped support for old php versions

SimpleSocket missing reutrn $out in case of error

added tests for php 7.1

Merge pull request #7 from RubtsovAV/master

removed the lower limit of pool size

removed php5.3 from the supported builds