Sync branches/forks at the server automatically

Currently, we're running 2.3.0 and looking at the forking feature. However, since we started using Stash and had a need for forking, we've been using branches to accomplish similar things, having development branches and sprint branches. Right now, the developers would like to have commits to master sync into the development branches. Yes I could write a bash script on cron that rebases master into the branch but I would prefer something server-side to sync the repos so that a commit hook can copy the commits over. Since I doubt this functionality exists, I'd like to raise a feature request and if it does, please point me in the right direction to accomplish this.