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/tempest/tests/utils.py b/tempest/tests/utils.py
index 571fc2a..0738201 100644
--- a/tempest/tests/utils.py
+++ b/tempest/tests/utils.py
@@ -17,41 +17,7 @@
 
 """Common utilities used in testing."""
 
-import nose.plugins.skip
-
-
-class skip_if(object):
-    """Decorator that skips a test if condition is true."""
-    def __init__(self, condition, msg):
-        self.condition = condition
-        self.message = msg
-
-    def __call__(self, func):
-        def _skipper(*args, **kw):
-            """Wrapped skipper function."""
-            if self.condition:
-                raise nose.SkipTest(self.message)
-            func(*args, **kw)
-        _skipper.__name__ = func.__name__
-        _skipper.__doc__ = func.__doc__
-        return _skipper
-
-
-class skip_unless(object):
-    """Decorator that skips a test if condition is not true."""
-    def __init__(self, condition, msg):
-        self.condition = condition
-        self.message = msg
-
-    def __call__(self, func):
-        def _skipper(*args, **kw):
-            """Wrapped skipper function."""
-            if not self.condition:
-                raise nose.SkipTest(self.message)
-            func(*args, **kw)
-        _skipper.__name__ = func.__name__
-        _skipper.__doc__ = func.__doc__
-        return _skipper
+from testtools import TestCase
 
 
 class skip_unless_attr(object):
@@ -66,7 +32,7 @@
             """Wrapped skipper function."""
             testobj = args[0]
             if not getattr(testobj, self.attr, False):
-                raise nose.SkipTest(self.message)
+                raise TestCase.skipException(self.message)
             func(*args, **kw)
         _skipper.__name__ = func.__name__
         _skipper.__doc__ = func.__doc__