Rename 'spec' directory to 'test'

QUnit is a test framework.

- Move 'spec' directory to 'test'
- Rename hello_spec.coffee to hello_test.coffee
- Override files.js to look for 'test' instead of 'spec'
- Setup 'npm test' & 'npm test-ci' scripts in package.json
- Override .travis.yml default script to use 'npm test-ci' not 'npm test'