make permission ip-only

goimports

zap logging

gortc.io imports

Add Close method

* Close underlying connection on method call
* Update multiplexer
* Block until goroutine is finished
* Add tests

Copy realm after allocation decode

After decode we would take realm by reference,
when creating permissions we would then fail
MessageIntegrity checks because this value would
be corrupted

Resolves #5

Bump gortc/turn and pion/stun

Fix atomic crash in STUN client on ARM

Expose Relayed address for Allocation

Add method Relayed() to allocation that exposes the Relayed
address for the allocation

initial version without zap

initial version