Allow environment variables to configure options
Allow environment variables to configure options

Changed from using Joi.assert() to Joi.validate(), use Joi.validate()'s
transformed result object for settings instead of using the input
parameter which may not be type safe.

edimoldovan/bell,tanepiper/bell,phoenixbox/bell,ldesplat/bell,geek/bell,pankajpatel/bell,lloydbenson/bell