Imporve Config tests:
Imporve Config tests:

- migrate to chai
- use shortcut for creating valid config where sensible

varya/gemini,racing-post/gemini,varya/gemini,pazone/gemini,gemini-testing/gemini,racing-post/gemini,vladislav-sevostyanov/gemini,HDevel/gemini,sergesemashko/gemini,pazone/gemini,HDevel/gemini