Test: Add 'nodeunit' dependency

Let's use the 'nodeunit' library as our testing
framework for now, as it feels a bit more like 
Node.js than jasmine or mocha.

Add it to package.json, so we can run 'npm test'
Test: Ensure-Auth: Basic authentication

Basic test for checking whether a request is
authenticated or not.
Test: Ensure-Auth: Mainframe access

Add simple tests for mainframe access
Test: Ensure-Auth: Circle access

Basic tests for circle access
Test: Auth-Ensure: Circle admin access

Tests related to being a circle administrator
Readme: Use 'npm test' for testing