added tests for Config class
added tests for Config class

dimagi/rapidsms,catalpainternational/rapidsms,catalpainternational/rapidsms,lsgunth/rapidsms,dimagi/rapidsms-core-dev,ken-muturi/rapidsms,rapidsms/rapidsms-core-dev,unicefuganda/edtrac,caktus/rapidsms,catalpainternational/rapidsms,dimagi/rapidsms,eHealthAfrica/rapidsms,eHealthAfrica/rapidsms,peterayeni/rapidsms,eHealthAfrica/rapidsms,lsgunth/rapidsms,unicefuganda/edtrac,peterayeni/rapidsms,dimagi/rapidsms-core-dev,caktus/rapidsms,peterayeni/rapidsms,caktus/rapidsms,lsgunth/rapidsms,ehealthafrica-ci/rapidsms,unicefuganda/edtrac,catalpainternational/rapidsms,ehealthafrica-ci/rapidsms,ehealthafrica-ci/rapidsms,peterayeni/rapidsms,lsgunth/rapidsms,ken-muturi/rapidsms,rapidsms/rapidsms-core-dev,ken-muturi/rapidsms