[RELEASE] -  publish version:  '1.2.1-rc27'.
[RELEASE] -  publish version:  '1.2.1-rc27'.

srijs/zipkin,thelastpickle/zipkin,hydro2k/zipkin,rjbhewei/zipkin,gneokleo/zipkin,coursera/zipkin,rjbhewei/zipkin,mzagar/zipkin,rjbhewei/zipkin,yshaojie/zipkin,prat0318/zipkin,mt0803/zipkin,jstanier/zipkin,srijs/zipkin,rocwzp/zipkin,jfeltesse-mdsol/zipkin,jstanier/zipkin,wuqiangxjtu/zipkin,srijs/zipkin,wuqiangxjtu/zipkin,jfeltesse-mdsol/zipkin,lqjack/zipkin,coursera/zipkin,thelastpickle/zipkin,mt0803/zipkin,hydro2k/zipkin,mzagar/zipkin,wuqiangxjtu/zipkin,gneokleo/zipkin,coursera/zipkin,prat0318/zipkin,lqjack/zipkin,lqjack/zipkin,mzagar/zipkin,betable/zipkin,mt0803/zipkin,thelastpickle/zipkin,rocwzp/zipkin,Yelp/zipkin,rocwzp/zipkin,betable/zipkin,gneokleo/zipkin,rjbhewei/zipkin,betable/zipkin,rocwzp/zipkin,prat0318/zipkin,Yelp/zipkin,jfeltesse-mdsol/zipkin,yshaojie/zipkin,hydro2k/zipkin,hydro2k/zipkin,Yelp/zipkin,wuqiangxjtu/zipkin,srijs/zipkin,mt0803/zipkin,jstanier/zipkin,betable/zipkin,Yelp/zipkin,prat0318/zipkin,yshaojie/zipkin,thelastpickle/zipkin,lqjack/zipkin,coursera/zipkin,jstanier/zipkin,gneokleo/zipkin,mzagar/zipkin,yshaojie/zipkin,jfeltesse-mdsol/zipkin