kubernetes: Fix Federation example in README (#1515)
kubernetes: Fix Federation example in README (#1515)

Remove `fallthrough` from the federation example in the README.  `fallthrough` isn't needed here and has no effect (federation has an implicit fallthrough for non-federated queries).  
It's inclusion is confusing.
ii/coredns,johnbelamaric/coredns,miekg/coredns,jremond/coredns,yongtang/coredns,coredns/coredns,miekg/coredns,johnbelamaric/coredns,ii/coredns,jremond/coredns,chrisohaver/coredns