Context:
While building the first increment for the ElasticSearch support, we had to remove a lot of integration tests to be able to ship the version. In this task, we should enable the testing of the migration again.

AT:

• on every commit it is tested again that the upgrade/migration in Optimize works.

Hint:
We need to think about how to provide several ElasticSearch instances on Jenkins and how to incorporate that into Optimize.