Fix session path

Dockerfile

@@ -29,10 +29,10 @@ RUN echo "Listen 8000" > /etc/apache2/ports.conf
 # configure mod_php
 RUN a2enmod php5
 RUN sed -e 's/upload_max_filesize = .*/upload_max_filesize = 8M/' \
-        -e 's,;session.save_path.*,session.save_path = "/run/mediawiki/sessions",' \
+        -e 's,;session.save_path.*,session.save_path = "/run/wordpress/sessions",' \
         -i /etc/php5/apache2/php.ini
 
-RUN mkdir /run/wordpress && \
+RUN mkdir -p /run/wordpress/sessions && \
     ln -sf /run/wordpress/wp-config.php /app/code/wp-config.php
 
 CMD [ "/app/code/start.sh" ]