add release notes for 2.7.0
add release notes for 2.7.0

fengshao0907/jdbi,hgschmie/jdbi,john9x/jdbi,omidp/jdbi,stevenschlansker/jdbi,jdbi/jdbi,christophercurrie/jdbi,zanebenefits/jdbi,11xor6/jdbi,voidifremoved/jdbi,kentyeh/jdbi,BernhardBln/jdbi,pennello/jdbi,hgschmie/jdbi,HubSpot/jdbi,HubSpot/jdbi,christophercurrie/jdbi,omidp/jdbi,jdbi/jdbi,hgschmie/jdbi,BernhardBln/jdbi,11xor6/jdbi,john9x/jdbi,pennello/jdbi,voidifremoved/jdbi,kentyeh/jdbi,jdbi/jdbi,fengshao0907/jdbi,zanebenefits/jdbi,stevenschlansker/jdbi