Update readme with instructions on how to build on 0.6.x
Update readme with instructions on how to build on 0.6.x

mixu/nwm,dougbo/lever,ellis/nwm,dougbo/lever,mixu/nwm,dougbo/lever,dougbo/lever,mixu/nwm,dougbo/lever,ellis/nwm,ellis/nwm,ellis/nwm,mixu/nwm,ellis/nwm,mixu/nwm