Backup gem v4

Upgrade the Backup cookbook to v4

I moved encrypt_with to the model as they no longer show it in config.rb in the example; feels wrong to assume every backup will be encrypted the same way.  Added an example to the test.

  + Add `data_dir` and `tmp_dir` to `resources/generate_config.rb` so we can specify our tmp path and where we store our data files.
  - Update `config.rb.erb` to support the new backupv4 style config.rb
  - Update `generic_model.conf.erb` to support encryption
    + Update how we declare the model name as well.