Update readme to show build status for the release branch
Update readme to show build status for the release branch

Former-commit-id: 55768ea9e930ad4885888527839ae948032803f6
Former-commit-id: 0a9c676b5bbcdb0a959b2f46de840e6c592f4dea
KorvinSzanto/concrete5,acliss19xx/concrete5,deek87/concrete5,hissy/concrete5,hissy/concrete5,rikzuiderlicht/concrete5,a3020/concrete5,KorvinSzanto/concrete5,mainio/concrete5,mainio/concrete5,concrete5/concrete5,deek87/concrete5,biplobice/concrete5,haeflimi/concrete5,mlocati/concrete5,haeflimi/concrete5,triplei/concrete5-8,biplobice/concrete5,hissy/concrete5,mlocati/concrete5,olsgreen/concrete5,concrete5/concrete5,mlocati/concrete5,biplobice/concrete5,jaromirdalecky/concrete5,haeflimi/concrete5,hissy/concrete5,jaromirdalecky/concrete5,acliss19xx/concrete5,concrete5/concrete5,a3020/concrete5,triplei/concrete5-8,KorvinSzanto/concrete5,deek87/concrete5,haeflimi/concrete5,biplobice/concrete5,olsgreen/concrete5,MrKarlDilkington/concrete5,MrKarlDilkington/concrete5,rikzuiderlicht/concrete5,mainio/concrete5,acliss19xx/concrete5,olsgreen/concrete5,concrete5/concrete5,triplei/concrete5-8,mlocati/concrete5,MrKarlDilkington/concrete5,jaromirdalecky/concrete5,jaromirdalecky/concrete5,deek87/concrete5,rikzuiderlicht/concrete5