Update go version in travis.yml (#4843)
Update go version in travis.yml (#4843)


qiuyesuifeng/tidb,ngaut/tidb,EvilMcJerkface/tidb,c4pt0r/tidb,wusphinx/tidb,8cbx/tidb,pingcap/tidb,kyle-wang/tidb,qiuyesuifeng/tidb,CodeRushing/tidb,c4pt0r/tidb,kyle-wang/tidb,tiancaiamao/tidb,CodeRushing/tidb,yangwenmai/tidb,Cofyc/tidb,c4pt0r/tidb,yuanwhy/tidb,kyle-wang/tidb,ngaut/tidb,XuHuaiyu/tidb,XuHuaiyu/tidb,ming-relax/tidb,mccxj/tidb,kyle-wang/tidb,EvilMcJerkface/tidb,mccxj/tidb,kyle-wang/tidb,ngaut/tidb,tiancaiamao/tidb,pingcap/tidb,yangwenmai/tidb,ngaut/tidb,Cofyc/tidb,c4pt0r/tidb,pingcap/tidb,pingcap/tidb,c4pt0r/tidb,c4pt0r/tidb,spongedu/tidb,spongedu/tidb,pingcap/tidb,Nify/tidb,coocood/tidb,pingcap/tidb,ngaut/tidb,wusphinx/tidb,coocood/tidb,ngaut/tidb,8cbx/tidb,yuanwhy/tidb,Nify/tidb,kyle-wang/tidb,cosmtrek/tidb,ming-relax/tidb,cosmtrek/tidb