Drop support for some older versions of PHP and Laravel in the next major release #41
Description
At the moment our versions constraints are brittle and its getting harder to anticipate where things might break due to wide range of supported software.
I suggest to limit support to the following versions to ease maintenance burden:
- PHP >= 7.4 (support for PHP 7.3 will end on December 6)
- Laravel >= 6.0 (this is the last version that still receives security fixes)
This also allows us to clean up some other dependencies a bit:
- "openzipkin/zipkin":
"~2.0.2|~3.0"=>"~3.0" - "phpunit/phpunit":
"~7.0|~8.0"=>"~9.0"
Users of older PHP/Laravel can still avail of older versions of the package.