Allow using both template engines

[MichaelPetrinolis]

The -t|--template option now supports a new value, TemplateEngine.Both, and sets it as the default value. This improves flexibility by allowing an additional template engine.

closes #119

[hishamco]

Could you please add a quick unit test to avoid such accidental breaks

Thanks

[hishamco]

We need to publish a patch release after this immediately

[MichaelPetrinolis]

Could you please add a quick unit test to avoid such accidental breaks

Thanks

Unfortunately the CommandLineApplication is not testable, as we cannot test the Execute Method.

To tell you the truth I added some tests to check that no exception is raised when you provide the correct args, but i did not published them, as the correct way to do it is to test the Execute callback with mocking the actual extractor. We need to check if the processors where added to the engine, if -t is not passed.

[hishamco]

I will check how I can test this later

Thanks