Add unittest2 as test req in setup.py

setup.py

@@ -25,6 +25,7 @@ long_description = ""
 with open("README.rst") as f:
     long_description = f.read()
 
+
 class DocCommand(Command):
 
     description = "generate or test documentation"
@@ -162,7 +163,7 @@ def run_setup(extensions):
         packages=['cassandra', 'cassandra.io'],
         include_package_data=True,
         install_requires=dependencies,
-        tests_require=['nose', 'mock', 'ccm'],
+        tests_require=['nose', 'mock', 'ccm', 'unittest2'],
         classifiers=[
             'Development Status :: 4 - Beta',
             'Intended Audience :: Developers',

tests/unit/test_metadata.py

@@ -1,4 +1,7 @@
-import unittest
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest # noqa
 
 import cassandra
 from cassandra.metadata import (TableMetadata, Murmur3Token, MD5Token,
@@ -128,6 +131,7 @@ class TestStrategies(unittest.TestCase):
         self.assertItemsEqual(rf3_replicas[MD5Token(100)], [host2, host3, host1])
         self.assertItemsEqual(rf3_replicas[MD5Token(200)], [host3, host1, host2])
 
+
 class TestTokens(unittest.TestCase):
 
     def test_protect_name(self):