Installation under Symfony 4.2.x not possible, after entering command "composer require php-http/httplug-bundle" composer says:
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Installation request for php-http/httplug-bundle ^1.14 -> satisfiable by php-http/httplug-bundle[1.14.0].
- php-http/httplug-bundle 1.14.0 requires php-http/cache-plugin ^1.6 -> satisfiable by php-http/cache-plugin[1.6.x-dev] but these conflict with your requirements or minimum-stability.
Installation failed, reverting ./composer.json to its original content.