Added a test serializing NonParametricRuptures
Added a test serializing NonParametricRuptures


Former-commit-id: 80a8954ac329bec1a9277626f3c388a83c3fdc7f [formerly 90776d3f6bf58c1d241f3e584327cb7cfc472c1e]
Former-commit-id: 099f6a9fae51fae445c5cb11762dff02cf7d2ca7
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine