Replace hardcoded 14.04 in Ubuntu node instructions
Replace hardcoded 14.04 in Ubuntu node instructions

mbrukman/flocker,jml/flocker,AndyHuu/flocker,1d4Nf6/flocker,mbrukman/flocker,lukemarsden/flocker,1d4Nf6/flocker,hackday-profilers/flocker,moypray/flocker,agonzalezro/flocker,lukemarsden/flocker,LaynePeng/flocker,w4ngyi/flocker,Azulinho/flocker,w4ngyi/flocker,Azulinho/flocker,hackday-profilers/flocker,hackday-profilers/flocker,moypray/flocker,w4ngyi/flocker,moypray/flocker,achanda/flocker,adamtheturtle/flocker,lukemarsden/flocker,adamtheturtle/flocker,achanda/flocker,mbrukman/flocker,adamtheturtle/flocker,agonzalezro/flocker,1d4Nf6/flocker,agonzalezro/flocker,achanda/flocker,AndyHuu/flocker,wallnerryan/flocker-profiles,wallnerryan/flocker-profiles,jml/flocker,jml/flocker,LaynePeng/flocker,LaynePeng/flocker,AndyHuu/flocker,Azulinho/flocker,wallnerryan/flocker-profiles