completed exposure model tests
completed exposure model tests


Former-commit-id: bed8c19b4ad1b502665cda36bc3f226a0f586c25 [formerly 10c680efa0c165bb4adf111e0d9462c35f15b9c6]
Former-commit-id: 8c35268d5f04040c07ecfc753eabdbec1c8c2b37
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine