Separate the PHP versions to multiple dockerfiles

Because there's some difference in installing some libraries
between PHP 5 and PHP 7. There must be multiple php dockerfiles.
For that I created 3 docker files each of a different version,
this will make it easy for the users to switch between the PHP
version by just editing the docker-compose file and not touching
the dockerfiles.

php/Dockerfile-php-56

@@ -0,0 +1,23 @@
+FROM php:5.6-fpm
+
+MAINTAINER Mahmoud Zalt <mahmoud@zalt.me>
+
+ADD ./laravel.ini /usr/local/etc/php/conf.d
+ADD ./laravel.pool.conf /usr/local/etc/php-fpm.d/
+
+RUN apt-get update && apt-get install \
+    libpq-dev -y \
+    curl
+
+# Install extensions using the helper script provided by the base image
+RUN docker-php-ext-install \
+    pdo_mysql \
+    pdo_pgsql
+
+RUN usermod -u 1000 www-data
+
+WORKDIR /var/www/laravel
+
+CMD ["php-fpm"]
+
+EXPOSE 9000