use the system time zone unless overridden in rapidsms.ini
use the system time zone unless overridden in rapidsms.ini

this should stop people from hard-coding and checking in the
timezone that we happen to be currently working in... looking
at _you_, @takinbo!

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