building and sharing maven artifacts

I'm currently using Bitbucket for my source code and Jenkins for CI, but I'm considering to switch to GitLab as it seems to have everything BitBucket and Jenkins have to offer, at least for what I need it for.

However, I'm experiencing some issues building my maven based projects wit GitLab CI.
The problem is that I have several "base" projects and several "real" projects.
Each real project depends on one or more of the base projects.
So in order to build a real project it needs the artifacts from one or more of the base projects.

With my jenkins setup, everything that gets build is stored in the local maven cache (.m2) which is accessible by all jenkins jobs,
but this doesn't seem to be possible with GitLab CI.
At least, not in such a way that different projects can access the same .m2 cache.

So my question is: is there a way with GitLab to store artifacts in a shared, but private location that is accessible for all my projects?

FYI: I'm using the GitLab.com service