spec: Add %changelog macro
spec: Add %changelog macro

With that, cockpituous will fill it with the actual release tag
descriptions.

weldr/welder-web,jkozol/welder-web,jkozol/welder-web,jkozol/welder-web,jkozol/welder-web,weldr/welder-web,weldr/welder-web,weldr/welder-web