implementing streams all the way solution to lower memory footprint and make writes smooth

- logins are streamed one by one
- requests are made for each one and the response converted into batches
- puts from these batches are pushed down one by one
- in the next step these puts are batched together at an ideal size and each batch pushed when it is big enough
- we pull from that batch stream whenever it is readable and levelup is done storing the last batch