Update encoding.py
Update encoding.py

Open and update messages are now valid JSON messages.
Update messages contains now the 'type' element.
dneiter/exabgp,earies/exabgp,dneiter/exabgp,PowerDNS/exabgp,benagricola/exabgp,benagricola/exabgp,blablacar/exabgp,earies/exabgp,PowerDNS/exabgp,fugitifduck/exabgp,benagricola/exabgp,lochiiconnectivity/exabgp,PowerDNS/exabgp,blablacar/exabgp,lochiiconnectivity/exabgp,blablacar/exabgp,lochiiconnectivity/exabgp,fugitifduck/exabgp,fugitifduck/exabgp,earies/exabgp,dneiter/exabgp