Update .travis.yml
Update .travis.yml


Former-commit-id: 93661fcd506b9b1b545d5756ad467c870286a883 [formerly c13e89cf1e7a5b81719d7278f162ddd4d294c838]
Former-commit-id: ae353b8c72a7839dd8ad4796d7cce85733327940
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine