Make GEM_EPHEM_NAME customizable via an env variable
Make GEM_EPHEM_NAME customizable via an env variable


Former-commit-id: 3daa6f7f7f1073e3ba597adb30ad524e9c695f2b
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine