heroku/hk — pull request #45 by bgentry (2013-12-18 17:34:13+00:00)
Title: output a confirmation after a modifying action

Still a WIP, I haven't touched the following commands yet:

```
hk sshkey-add [] # add ssh public key
hk transfer [-a ] # transfer app ownership to a collaborator (extra)
hk transfer-accept [-a ] # accept an inbound app transfer (extra)
hk transfer-cancel [-a ] # cancel an outbound app transfer (extra)
hk transfer-decline [-a ] # decline an inbound app transfer (extra)
hk transfers [-a ] # list existing app transfers (extra)
hk unset [-a ] ... # unset env var
hk update #
```