add test for sample_evidence
add test for sample_evidence

HazyResearch/deepdive,closedLoop/sampler,HazyResearch/sampler,closedLoop/sampler,sai16vicky/sampler,sai16vicky/sampler,closedLoop/sampler,HazyResearch/deepdive,HazyResearch/deepdive,HazyResearch/deepdive,HazyResearch/sampler,sai16vicky/sampler,sai16vicky/sampler,HazyResearch/sampler,closedLoop/sampler