removed some superfluous tests
removed some superfluous tests

basically, these tests were testing functionality of an abstract class and its methods that were not used in production

they were testing unnecessary code =(


Former-commit-id: e2a6cbc6cb2c416e3b703314422bd7cd693b5cad
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine