Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires mammatus/cron dev-e432867895cba8dfc4ef844caa9185176c581b69 -> satisfiable by mammatus/cron[dev-e432867895cba8dfc4ef844caa9185176c581b69]. - mammatus/cron dev-e432867895cba8dfc4ef844caa9185176c581b69 requires mammatus/app dev-master -> found mammatus/app[dev-master] but it does not match your minimum-stability.

Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires mammatus/cron dev-83/merge, found mammatus/cron[dev-e432867895cba8dfc4ef844caa9185176c581b69] but it does not match the constraint.