removed unittest2 from mllib testing.py

python/pyspark/testing/mllibutils.py

@@ -15,16 +15,7 @@
 # limitations under the License.
 #
 
-import sys
-
-if sys.version_info[:2] <= (2, 6):
-    try:
-        import unittest2 as unittest
-    except ImportError:
-        sys.stderr.write('Please install unittest2 to test with Python 2.6 or earlier')
-        sys.exit(1)
-else:
-    import unittest
+import unittest
 
 from pyspark import SparkContext
 from pyspark.serializers import PickleSerializer