There needs to be a way to specify either a blacklist for HEADS (test, testing, whatever) or a whitelist for HEADS (master, develop, 1.0, 2.0, 3.0) so that what gets splitted out can be better controlled.

Related to dflydev/git-subsplit#6 since the pushing of a branch is not easy to "undo" once it is pushed. Right now someone would have to manually clone each subsplit and delete the branch from each repository.