COMMON_EXTRA_APPS env variable not doing anything

Hi, we are trying to use the COMMON_EXTRA_APPS env variable to more easily deploy Mayan EDMS with our custom addons. Sadly it looks like the env variable is not implemented in the Docker scripts.

It would be great if it were to be implemented. It's not a dealbreaker, but it can make deploying Mayan EDMS much easier and faster for everyone.

Steps to reproduce

• Launch the docker install with the COMMON_EXTRA_APPS env variable.

Expected result

• COMMON_EXTRA_APPS is automatically configured in Mayan EDMS after launching the docker containers.

Actual result

• The COMMON_EXTRA_APPS variable is silently ignored.