Release v0.7.0

Added

• New style request/response implementation (#59)

• The ErrSlowConsumer now include sid and subject when a message is dropped (#58)

• New options pending_msgs_limit and pending_bytes_limit were added to subscribe API
  for controlling limits of pending data waiting to be processed before dropping messages.
  (#58)

• Msg type now uses __slots__ (#58)

Improved

• More performant inbox generation via NUID approach (#57)

Fixed

• Each Subscription now has a task so coroutines no longer
  cause head of line blocking to each other.
  (#58)

Changed

• request API when a callback is not passed now blocks and waits for response
  using the new style request/response API which is less chatty over
  the network.
  (#59)

Deprecated

• subscribe_async will be deprecated in next release,
  as a workaround a task can be created inside of a handler and would
  result in more control than can have in the library.