Update CHANGELOG.md 
Update CHANGELOG.md 

Mentions min CPU limit change in backward incompatibilities section.
nak3/nomad,nak3/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,nak3/nomad,burdandrei/nomad,burdandrei/nomad,hashicorp/nomad,dvusboy/nomad,hashicorp/nomad,dvusboy/nomad,nak3/nomad,dvusboy/nomad,nak3/nomad,burdandrei/nomad,nak3/nomad,nak3/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,burdandrei/nomad,hashicorp/nomad,dvusboy/nomad,dvusboy/nomad