Needed to update race_delete in order to test the situation when the server is under heavy load.

There can be two behaviours:
1)the server manages to complete the task before the second call of repo deletion is issued.
So when the second call will be issued we will have 404 retuned.
2)the server does not manage to complete the task before second call of repo delete is issued(so the second task is created).
Here we have to ensure that the seond task failes with 404 code 'missing resource'.
Merge branch 'master' of github.com:RedHatQE/pulp-automation