Should HTTP client protocol be async by default?

[bsless]

Title says it all.
A more generic signature would be [request options success fail]

wdyt?

[borkdude]

@bsless We can have both sync and async functions.

I think it's best to focus on the JSON example first, to limit the scope and decide on a good starting point for this library.
One discussion going on at the moment is this one #3 (comment)