doc: point out we only support python-2 for now
doc: point out we only support python-2 for now

go-python/gopy,go-python/gopy,kellrott/gopy,go-python/gopy-gen,lifei/gopy,go-python/gopy-gen,ericsnowcurrently/gopython-gopy,ericsnowcurrently/gopython-gopy,kellrott/gopy,lifei/gopy