Develop

Hello,

I added options to query : 
- min_score => Required when we want to filter pertinence results 
- facets/all_terms => Allow you to pass the all_terms (bool) param for facets
- facets/field => You can now specify the field for facet. 

I did this fix because I migrated my project to searchkick and needed this options. I am not an expert of ES, so, be critical, I maybe made huge mistakes !