Add the environment variable of the PHP version

Author: nanoninja

Diff for: .env

@@ -5,6 +5,9 @@
 # Nginx
 NGINX_HOST=localhost
 
+# PHP
+PHP_VERSION=latest
+
 # MySQL
 MYSQL_HOST=mysql
 MYSQL_DATABASE=test

Diff for: docker-compose.yml

@@ -18,7 +18,7 @@ services:
             - php
             - mysqldb
     php:
-        image: nanoninja/php-fpm
+        image: nanoninja/php-fpm:${PHP_VERSION}
         restart: always
         volumes:
             - "./etc/php/php.ini:/usr/local/etc/php/conf.d/php.ini"