0.2.0

CHANGES:

• client: report exceptions before closing the response body
  (#135)
• server: process requests after EOF
  (#136)
• surface (body) write errors through flush
  (#138)
  • Body.Writer.flush now takes a callback of the type
    ([ `Written | ` Closed] -> unit), informing the caller whether the
    previous writes have been written or whether the output channel was
    closed.