* Fix Socket <-> PhxTimer strong reference cycle

* Fix Channel strong reference cycles

* Fix Socket <-> Channel reference cycle

* Update CHANGELOG.md

* Fix Socket.disconnect not calling onClose

Since connection.delegate is nil'd out, the Socket wasn't getting the
`websocketDidDisconnect(socket:error:)` delegate message so it'd never
call onClose callbacks.

This also fixes an issue where the Socket would never be deinit'd
because the current run loop had a strong reference to it (via the
heartbeatTimer)

* Stop timer & fire onClose directly

instead of relying on the `onConnectionClosed()` function.
`onConnectionClosed()` does some additional things that we don't want
(i.e. starting the reconnect timer) to happen when a Socket is
explicitly disconnected.

* Add tests for disconnect() calling onClose

* Removed copy frameworks for carthage

* Update example project