(feature) Optimizing minds index

This query change relies on the state.keyword being set on the index.

The changes in postman will require the minds-kite index be recreated.

#217 (closed)

{
	"settings" : {
        "index" : {
            "number_of_shards" : 1
        }
    },
	"mappings": {
		"user-state": {
			"properties": {
				"user_guid":{ "type": "long" },
				"reference_date": { "type": "date"},
				"state": { "type": "keyword" },
				"previous_state": { "type": "text" },
				"activity_percentage": { "type": "double" }
			}
		}
	}å
}