Ensure enough memory for Composer
Resolve a composer.json for an old Laravel 5.2 code base now consumes
1.8 GiB of RAM.
It seems reasonable to allow this container specialized to run PHP
CLI applications to let the application to consume 2 GiB of RAM.
Test Plan: composer install
Reviewed By: dereckson
Maniphest Tasks: T1638
Differential Revision: https://devcentral.nasqueron.org/D2367