fixed some typo errors in the coupons fixture
fixed some typo errors in the coupons fixture

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