Delete graduated concurrency files

Per the new process, we will not be keeping graduated files around
on the master branch of incubator.

Co-Authored-By: Ihar Hrachyshka <ihrachys@redhat.com>
Change-Id: Id0469b31a51ee6482d8b7bcca7664854d705c102
Closes-Bug: 1371697
Updated from global requirements

Change-Id: I1cbb40e85dbbdb2c5e8426e1b40af9eb809fa9be