using full ocse as test data slows down testing

[cknoll]

Because the OCSE currently is the pilot use case of pyerk many unittests are based on data from that erk package. However, as more and more content is introduced in the OCSE these same tests get slower (because for isolation purposes the data is reloaded every time).

Solution: There should be separate test data set (which is preferably automatically created as a subset of the original OCSE).