Have you ever encounter slow composer package install and seeing this warning message?
Failed to download vendor/package from dist: The zip extension and unzip command are both missing, skipping.
Composer will then trying to download the package from source or cloning from cache.
This is most probably because of missing PHP zip module. Here's how you can install it in Ubuntu 14.04
apt install php7.0-zip
composer install is a lot more faster.