copied capistrano support from gerousia

@acozine as far as I can tell, this is all the files you added/modified in gerousia.  The [gerousia README](https://github.com/curationexperts/gerousia/blob/master/README.md) says that you can run 

```bash
bundle exec cap sandbox deploy
``` 

but that fails for me in _both_ absolute and gerousia with:
```bash
 INFO [160f77b9] Running /usr/bin/env mkdir -p /tmp/gerousia/ on casedeploy
DEBUG [160f77b9] Command: /usr/bin/env mkdir -p /tmp/gerousia/
cap aborted!
SocketError: getaddrinfo: nodename nor servname provided, or not known
```