Added exporter for stats [skip CI]
Added exporter for stats [skip CI]


Former-commit-id: 7c04ee103145014f6bb010384c3a0b2e475d903a [formerly a3c9f073f014e27b580201bcae11aeaa7baf99d4]
Former-commit-id: 6ed964d47143f449de3f46e72f7cecc0346722ef
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine