update the transports

[daviddias]

This PR updates the transport dependencies and adapts swarm to work with the interface-transport and interface-connection, without compromising any guarantees or interface.

[dignifiedquire]

Is this using a setter method, or direct property access?

[daviddias]

This is 'pre Identify factor out', after the refactor it should always be getPeerInfo. I'm just doing things gradually to not break too many at once.

[dignifiedquire]

but you could just change the impl on the connection so it is a setter, then you don't need to break anything:

function Connection () {
  // ...
}

Object.setProperty(Connection.prototype, 'peerId', {
  set (id) {
    this._peerId = id
    // other things to do
  }
})