change php to php-fpm

Dockerfile

@@ -12,4 +12,4 @@ ENV COMPOSER_ALLOW_SUPERUSER=1
 RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
 RUN composer install
 
-CMD ["php"]
\ No newline at end of file
+CMD ["php-fpm"]
\ No newline at end of file