0.3.0-alpha.14

0.3.0-alpha.14 - 2019-4-15

• Updated to new nightly futures_api.
• Changed Forward combinator to drop sink after completion, and allow !Unpin Sinks.
• Added 0.1 <-> 0.3 compatability shim for Sinks.
• Changed Sink::Item to a generic parameter Sink<Item>, allowing Sinks to accept
  multiple different types, including types containing references.
• Changed AsyncRead and AsyncWrite to take Pin<&mut Self> rather than &mut self.
• Added support for no_std + alloc use.
• Changed join and try_join combinators to functions.
• Fixed propagation of cfg-target-has-atomic feature.