Add refresh command

The command will stash, fetch, rebase, bundle, migrate, and unstash.
If there are merge conflicts it will break, if there is no stash, then
it will not unstash
Merge branch 'master' of https://github.com/haosu/dot

* 'master' of https://github.com/haosu/dot:
  Change slate config chaining
  Add more slate config
  Add slate config