Make synchronous curl timeout configurable

[jameshiew]

Calling something like curl.post synchronously (i.e without a callback) has a maximum timeout of 10s as the curl call is wrapped by a job with a 10s timeout.

-- curl.lua
  if opts.callback then
    return job:start()
  else
    job:sync(10000)
    return response
  end

Rather than passing in 10000, could an extra option be passed to the curl method instead? e.g. timeout

  if opts.callback then
    return job:start()
  else
    local timeout = 10000
    if opts.timeout then
        timeout = opts.timeout
    end
    job:sync(timeout)
    return response
  end

[Conni2461]

why not. PR welcome :)