sending a json body with http:request

[Tim Fletcher]

> You'd think so :) In the hope of saving someone else the time I spent
> debugging this (probably more than once), I'll let you know that
> http:request accepts only flat strings and binaries, _not_ iolists.

Yes, and you don't even need to debug it or check the source to
verify; just check the type definitions in the docs:

    http://erlang.org/doc/man/http.html#id2275333

:)