changes to README
changes to README

Knewton/docker-zipkin,frenchfrywpepper/docker-zipkin,itszero/docker-zipkin,jfeltesse-mdsol/docker-zipkin,abesto/docker-zipkin,gneokleo/docker-zipkin,openzipkin/docker-zipkin,jfeltesse-mdsol/docker-zipkin,eirslett/docker-zipkin,tedyoung/docker-zipkin,kristofa/docker-zipkin,tedyoung/docker-zipkin,openzipkin/docker-zipkin,lispmeister/docker-zipkin,niccaluim/docker-zipkin,itszero/docker-zipkin