update raspberrypi3 install procedure (#148)
update raspberrypi3 install procedure (#148)

install stable version of libreadline6 based on comment from MaxTG
shsmith/electrumx,erasmospunk/electrumx,erasmospunk/electrumx,bauerj/electrumx,Groestlcoin/electrumx-grs,Groestlcoin/electrumx-grs,thelazier/electrumx,Crowndev/electrumx,Crowndev/electrumx,shsmith/electrumx,bauerj/electrumx,thelazier/electrumx