set default memory limit to 128m

Dockerfile

@@ -52,7 +52,7 @@ RUN a2enmod rewrite
 # configure mod_php
 RUN crudini --set /etc/php/7.0/apache2/php.ini PHP upload_max_filesize 8M && \
     crudini --set /etc/php/7.0/apache2/php.ini PHP post_max_size 8M && \
-    crudini --set /etc/php/7.0/apache2/php.ini PHP memory_limit 64M && \
+    crudini --set /etc/php/7.0/apache2/php.ini PHP memory_limit 128M && \
     crudini --set /etc/php/7.0/apache2/php.ini Session session.save_path /run/app/sessions
 
 RUN mv /etc/php/7.0/apache2/php.ini /etc/php/7.0/apache2/php.ini.orig && ln -sf /app/data/php.ini /etc/php/7.0/apache2/php.ini