Using unittest2 in place of unittest

Used for Python 2.6 compatibility in testing.
diff --git a/tests/test_channel.py b/tests/test_channel.py
index 2651fcd..4141353 100644
--- a/tests/test_channel.py
+++ b/tests/test_channel.py
@@ -3,7 +3,7 @@
 
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'
 
-import unittest
+import unittest2 as unittest
 import datetime
 
 from googleapiclient import channel
diff --git a/tests/test_discovery.py b/tests/test_discovery.py
index b8cc959..ccc69c2 100644
--- a/tests/test_discovery.py
+++ b/tests/test_discovery.py
@@ -33,7 +33,7 @@
 import os
 import pickle
 import sys
-import unittest
+import unittest2 as unittest
 import urlparse
 import StringIO
 
diff --git a/tests/test_errors.py b/tests/test_errors.py
index 0cef892..9af8490 100644
--- a/tests/test_errors.py
+++ b/tests/test_errors.py
@@ -21,7 +21,7 @@
 __author__ = 'afshar@google.com (Ali Afshar)'
 
 
-import unittest
+import unittest2 as unittest
 import httplib2
 
 
diff --git a/tests/test_http.py b/tests/test_http.py
index c0ec5f9..a3ff0ac 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -27,7 +27,7 @@
 import httplib2
 import logging
 import os
-import unittest
+import unittest2 as unittest
 import urllib
 import random
 import StringIO
diff --git a/tests/test_json_model.py b/tests/test_json_model.py
index fec7191..462038a 100644
--- a/tests/test_json_model.py
+++ b/tests/test_json_model.py
@@ -26,7 +26,7 @@
 import copy
 import json
 import os
-import unittest
+import unittest2 as unittest
 import httplib2
 import googleapiclient.model
 
diff --git a/tests/test_mocks.py b/tests/test_mocks.py
index 34cc8a9..6ccc427 100644
--- a/tests/test_mocks.py
+++ b/tests/test_mocks.py
@@ -24,7 +24,7 @@
 
 import httplib2
 import os
-import unittest
+import unittest2 as unittest
 
 from googleapiclient.errors import HttpError
 from googleapiclient.errors import UnexpectedBodyError
diff --git a/tests/test_model.py b/tests/test_model.py
index 1d48194..6506cfc 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -23,7 +23,7 @@
 
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'
 
-import unittest
+import unittest2 as unittest
 
 from googleapiclient.model import BaseModel
 from googleapiclient.model import makepatch
diff --git a/tests/test_protobuf_model.py b/tests/test_protobuf_model.py
index b765943..b47812f 100644
--- a/tests/test_protobuf_model.py
+++ b/tests/test_protobuf_model.py
@@ -22,7 +22,7 @@
 
 __author__ = 'mmcdonald@google.com (Matt McDonald)'
 
-import unittest
+import unittest2 as unittest
 import httplib2
 import googleapiclient.model
 
diff --git a/tests/test_schema.py b/tests/test_schema.py
index eb41adf..8d07fed 100644
--- a/tests/test_schema.py
+++ b/tests/test_schema.py
@@ -19,7 +19,7 @@
 
 import json
 import os
-import unittest
+import unittest2 as unittest
 import StringIO
 
 from googleapiclient.schema import Schemas