Non feature branches

Good points. Leaving as it is sounds good. I wouldn't make the variable name longer. I can live with the view that the main branch is not a non-feature branch per se, but another type of branch that is neither a feature branch, nor a normal non-feature branch. 

I think you can remove the surrounding double-quotes from the argument to `echo`, i.e. `echo $non_feature_branch_names | tr ...`