Erro ao usar o composer

[LucsDantas]

composer require developersrede/magento2
Using version ^1.2 for developersrede/magento2
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

Problem 1
- Installation request for developersrede/magento2 ^1.2 -> satisfiable by developersrede/magento2[1.2.1].
- developersrede/magento2 1.2.1 requires developersrede/erede-php ^3.0 -> satisfiable by developersrede/erede-php[3.0.0, 3.0.1, 3.0.2] but these conflict with your requirements or minimum-stability.

Installation failed, reverting ./composer.json to its original content.