Add libvpx to brew install
Created by: alexagv
Fixes #133 (closed) brew install gst-plugins-good does not include libvpx by default causing the rtpfecserver example to fail as it utilizes vp8enc
Created by: alexagv
Fixes #133 (closed) brew install gst-plugins-good does not include libvpx by default causing the rtpfecserver example to fail as it utilizes vp8enc