Your requirements could not be resolved to an installable set of packages. Problem 1 - webimpress/composer-extra-dependency 0.2.2 requires composer-plugin-api ^1.1 -> found composer-plugin-api[2.2.0] but it does not match the constraint. - zendframework/zend-stratigility[2.2.0, ..., 2.2.2] require webimpress/http-middleware-compatibility ^0.1.4 -> satisfiable by webimpress/http-middleware-compatibility[0.1.4]. - webimpress/http-middleware-compatibility 0.1.4 requires webimpress/composer-extra-dependency ^0.2.2 -> satisfiable by webimpress/composer-extra-dependency[0.2.2]. - Root composer.json requires zendframework/zend-stratigility ^2.2 -> satisfiable by zendframework/zend-stratigility[2.2.0, 2.2.1, 2.2.2].

Process completed with exit code 2.