raise dependency on laminas-http 2.18

raise dependency on PHP 8.0

raise dependency on PHP 7.4
raise dependency on laminas-diactoros 2.0

keep compatibility using laminas-zendframework-bridge
  as this is only used using compat autolader

raise dependency on laminas-http 2.15

raise dependency on PHP 7.3
switch to phpunit9

switch to phpunit7