Add support for adding PHP extensions

src/linux.sh

@@ -1,6 +1,8 @@
 sudo add-apt-repository ppa:ondrej/php -y
 sudo apt update -y
+sudo mkdir -p /run/php
 sudo apt install -y php$1 curl
+sudo apt autoremove -y
 sudo update-alternatives --set php /usr/bin/php$1
 sudo curl -s https://getcomposer.org/installer | php
 sudo mv composer.phar /usr/local/bin/composer