finagle|finatra|scrooge|ts: Start every workflow with a clean slate
finagle|finatra|scrooge|ts: Start every workflow with a clean slate

Problem

OS builds are failing because of a compile error caused by generated code that
has been saved on the file system but the code has been removed in a recent
commit.

Solution/Result

Blowing away the cached files for each workflow has [[https://github.com/twitter/finatra/pull/570 | proven to help ]],
so let's do that as an interim solution.

JIRA Issues: CSL-11456

Differential Revision: https://phabricator.twitter.biz/D779807

twitter/finatra,twitter/finatra,twitter/finatra