Use testtools as the base testcase class.

Use testtools as the base unittest test case class towards to
parallelizing the test runs. Catch places where setUp and tearDown
were not being chained properly, and fix these problems.Remove
custom skip, using testtools.skip instead. Add TestResourceManager.

Part of blueprint speed-up-tempest

Change-Id: I8e7b5686b22969a0f3db96100a357c93a4d5c03f
diff --git a/tools/pip-requires b/tools/pip-requires
index fcf1690..dcc859f 100644
--- a/tools/pip-requires
+++ b/tools/pip-requires
@@ -1,7 +1,7 @@
 anyjson
 nose
 httplib2>=0.7.0
-unittest2
+testtools
 lxml
 boto>=2.2.1
 paramiko