Release 1.6.0

Proposed Tag Text:
```text
"Because you can't always blame Canada"

cerner_splunk Cookbook Release 1.6.0
- Support for Windows Forwarders
- Support for arbitrary 'app' configuration
- Beginnings of an open source contribution process.
```

Also available for review is the comparison from the last tag to the current stable: https://github.com/cerner/cerner_splunk/compare/1.5.0...e37500d731f160741cb2a3f360c83cca6ee80f7e

And all issues and pull requests toward this milestone:
https://github.com/cerner/cerner_splunk/issues?q=milestone%3Av1.6.0