Ring2SIP: Forward Ring Doorbell Calls to SIP and Vice Versa

[fsalomon]

Hi there! Just finished this: https://github.com/fsalomon/ring2sip

There have been a bunch of people asking about this and I needed it as well, so here you go.

Why?
The Ring App works fine for families, but not for businesses: Ring doesn't support SSO. Off-duty staff shouldn't be bothered with business Ring Calls. Also a PBX has so many features that can be useful for a Doorbell as well like call routing/hunt groups, time-based announcements and more.