How to share a build-matrix of jobs between multiple projects

We have a project that supports plugins. The main project has multiple version and editions. And we test the plugins against each one of those.

So assuming we have 3 version of the main application, and 20 plugins. Now each of our plugin repos has a .travis.yml section like this:

  - name: MyApp 1.2.x
    env: VERSION=1.2.x
  - name: MyApp 1.3.x
    env: VERSION=1.3.x
  - name: MyApp 2.0.x
    env: VERSION=2.0.x

Now when we deprecate a version, or add a new version for the main app, we have to go and update 20 plugin repo’s to add/remove those versions to/from the .travis.yml files.

I would like to ease the maintenance by having a single place, or a single command for that matter, to update the matrix for all plugins at once.

Any advice on (or alternatives) how to achieve this?