* Move app name, usage and version to constants
* Delegate cli.Action to hh.Action
* Add hh.Action unit test
Add app test using example functions
Assign cli.Action to hh.Action
Declare and initialize hh.ActionWriter, so TestAction can swap the writer and test the output
Remove app_test.go since testing.runExample can not capture hh.ActionWriter and action_test.go is testing output
Type hh.ActionWriter to io.Writer, so unit test can use bytes.Buffer
Merge pull request #1 from simeonwillbanks/test-hh

Test HH