Remove the NegativeAutoTest Framework

Since it's not really used and a bit complex. It was only used
for negative compute flavor tests, and I think we can live easily
without these tests.

Change-Id: Iab676ae9bf95ee858c5e748c9579f7778e87bd77
diff --git a/.coveragerc b/.coveragerc
index 51482d3..449e62c 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -1,4 +1,4 @@
 [run]
 branch = True
 source = tempest
-omit = tempest/tests/*,tempest/scenario/test_*.py,tempest/api_schema/*,tempest/api/*
+omit = tempest/tests/*,tempest/scenario/test_*.py,tempest/api/*