add legacy import support for MockRouter
add legacy import support for MockRouter

ehealthafrica-ci/rapidsms,caktus/rapidsms,eHealthAfrica/rapidsms,peterayeni/rapidsms,caktus/rapidsms,ehealthafrica-ci/rapidsms,eHealthAfrica/rapidsms,eHealthAfrica/rapidsms,lsgunth/rapidsms,lsgunth/rapidsms,peterayeni/rapidsms,lsgunth/rapidsms,catalpainternational/rapidsms,peterayeni/rapidsms,caktus/rapidsms,peterayeni/rapidsms,catalpainternational/rapidsms,ehealthafrica-ci/rapidsms,lsgunth/rapidsms,catalpainternational/rapidsms,catalpainternational/rapidsms