Refactor creation of test plugins
Refactor creation of test plugins

linus-sherrill/sprokit,Kitware/sprokit,linus-sherrill/sprokit,mathstuf/sprokit,Kitware/sprokit,Kitware/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,mathstuf/sprokit,Kitware/sprokit