Unhandled promise rejection after fresh install

After I was installed `stacker-cli` on a fresh ubuntu machine, I executed `stacker -v` and got this at the end of the usage block.

```
(node:3187) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: ENOENT: no such file or directory, open '/root/.stacker/links.json'
```