To build this demo need to change openssl paths in ./src/github.com/pions/webrtc/internal/dtls/dtls.go
for example:
/*
#cgo linux windows pkg-config: libssl libcrypto
#cgo linux CFLAGS: -Wno-deprecated-declarations
#cgo darwin CFLAGS: -Wno-deprecated-declarations
#cgo darwin LDFLAGS: -L/Users/user/dev/pions_gomobile/openssl-ios/lib/ -lssl -lcrypto
#cgo windows CFLAGS: -DWIN32_LEAN_AND_MEAN
#include "dtls.h"
*/