Updated chef-solo deployment to work with current versions

With this PR I was able to deploy huginn to a DigitalOcean Ubuntu 12.04 droplet with 1GB of RAM (the 512MB droplet does not seem to work)

To test it you need to pull this branch and modify `deployment/site-cookbooks/huginn_production/recipes/default.rb`as follows:
```
repo "https://github.com/dsander/huginn.git"
branch "chef-solo"
```