Use dynamic ports exposure when starting GitLab
Description
This MR makes it possible to start more than one GitLab container at a time. Previous limitation was binding 80:80 port, but now we are going to use dynamic ports exposure.
Why this MR is needed?
We want to test GitLab Geo, and it means that we need to run two GitLab containers in parallel.
Related issues
Closes #96 (closed)