added mocha and chai to package.json to avoid npm 3 warnings
added mocha and chai to package.json to avoid npm 3 warnings

jacekpolak/generator-yeogurt,OnkelTem/generator-yeogurt,dgoncalves1/generator-yeogurt,larsonjj/generator-yeogurt,markbrouch/generator-yeogurt,dgoncalves1/generator-yeogurt,larsonjj/generator-yeogurt,jacekpolak/generator-yeogurt,markbrouch/generator-yeogurt,OnkelTem/generator-yeogurt