Install and update Composer

install-composer

#!/usr/bin/env bash

set -euo pipefail

echo 'Installing Composer...'

if [ -f /usr/bin/php ]; then
    curl -sS https://getcomposer.org/installer | php
    sudo mv composer.phar /usr/local/bin/composer
else
    echo 'Composer needs PHP in order to be installed' >&2
    exit 1
fi