Do not quit after branch deletion

Hello, thanks for this project! I use it every day.
I have one suggestion not to quit the program after deleting a branch. Because I tend to do that in batches, and it’s a bit annoying having to restart git brunch after each branch deletion.
Unfortunately, I am not very familiar with Haskell so it would take me a lot of time to create a pull request, but I may give it a try.
Thanks.