Added better error messaging to TestScript module.
Added better error messaging to TestScript module.

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