[version] update changelog, mentioned 1.8.7-p249
[version] update changelog, mentioned 1.8.7-p249

pauloconnor/sensu,quodlibetor/sensu,cread/sensu,npe9/sensu,Tapjoy/sensu-mirror,javrasya/sensu,crewton/sensu,sensu/sensu,rbramwell/sensu,m4ce/sensu,yonglehou/sensu,roobert/sensu,somic/sensu,zuazo-forks/sensu,upfluence/sensu,withnale/sensu,miyakawataku/sensu,keymone/sensu,portertech/sensu,bf4/sensu,solarkennedy/sensu