Suggestion: add a few settings to apache config and php.ini to help sanitize the setup

[kobuki]

Thanks for the easy to use image and compose config.

After a successful deployment I've discovered a few points that you might want to address.

• look at the setup check page after deployment and modify the Dockerfile so that there are no warnings at all
• the base path should be configurable, now it forces /, but it sometimes makes it pretty hard to proxy properly (we're using a reverse proxy with https termination and a specific url path), if not impossible

All these changes can be done inside the container and then committed, but it would make it a lot easier if the base image wouldn't need to be modified.