Cocoapod subspec

This revision changes the Cocoapod spec allowing the installation of the SDK as a standalone framework without the WebRTC framework.

Caution

Beware, the WebRTC framework is still needed in order to compile and run the application when using the Kaleyra Video SDK.
You are supposed to use the Kaleyra Video SDK as a standalone framework only when you are integrating a third party video solution framework having WebRTC as dependency. Moreover, you are responsible for using a compatible WebRTC module

For more information head over to our installation guide