make -f Makefile.doc (#3633)
make -f Makefile.doc (#3633)

Preparing a release; don't want to end up with a dirty repo again.

Signed-off-by: Miek Gieben <00b357f94cf3a1145a32703fb42e2d80418ab806@miek.nl>
miekg/coredns,johnbelamaric/coredns,miekg/coredns,johnbelamaric/coredns,coredns/coredns,yongtang/coredns,chrisohaver/coredns