post https://query.kissmetrics.io/v3/queries
{
"product_id": "1234",
"query_type": "ab_test",
"query_params": {
"variation_property_index": 125, // Welcome email variation
"conversion_event_index": 957, // Premium Subscription
"start_date": "1498494140", // Mon Jun 26 2017 09:22:20 GMT-0700 (PDT)
"end_date": "1505889399", // Tue Sep 19 2017 23:36:39 GMT-0700 (PDT)
"bucket_size": 604800 // 7 days
}
}