bundle install fixes for berkshelf2

During testing of the berkshelf2 build I got the following errors:

```
STDERR: ERROR:  While executing gem ... (Gem::DependencyError)
    Unable to resolve dependencies: ridley requires buff-extensions (~> 0.3); buff-config requires buffextensions (~> 0.3); varia_model requires buff-extensions (~> 1.0)
```

This fixes the issue.