Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires react-parallel/pool-tests dev-41630dff15425defd65490c2fb3e9d644f86e6eb -> satisfiable by react-parallel/pool-tests[dev-41630dff15425defd65490c2fb3e9d644f86e6eb]. - react-parallel/pool-tests dev-41630dff15425defd65490c2fb3e9d644f86e6eb requires react-parallel/contracts ^2@dev -> found react-parallel/contracts[2.x-dev] 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 react-parallel/pool-tests dev-56/merge, found react-parallel/pool-tests[dev-41630dff15425defd65490c2fb3e9d644f86e6eb] but it does not match the constraint.