Consider using official cocoapod for webrtc instead of maintaining our own

[atsakiridis]

Currently Google seems to be working on it and based on their issue it's not ready yet. Still there exists a pod that seems to be maintained by Google.

I have already asked about that so let's make sure we monitor closely and see if that's the case. If so we can discontinue maintaining a webrtc cocoapod ourselves.

[atsakiridis]

Apparently, they do provide development pods for now; check first section here, which I think is good enough so we can probably start using those when we decide to bite the bullet and upgrade.