remove python2 specific code

IPython/core/tests/test_interactiveshell.py

@@ -16,10 +16,8 b' import shutil'
 import sys
 import tempfile
 import unittest
-try:
-    from unittest import mock
-except ImportError:
-    import mock
+from unittest import mock
+
 from os.path import join
 
 import nose.tools as nt

IPython/core/tests/test_paths.py

@@ -4,11 +4,7 b' import shutil'
 import sys
 import tempfile
 import warnings
-
-try:                    # Python 3
-    from unittest.mock import patch
-except ImportError:     # Python 2
-    from mock import patch
+from unittest.mock import patch
 
 import nose.tools as nt
 from testpath import modified_env, assert_isdir, assert_isfile

IPython/core/tests/test_run.py

@@ -20,11 +20,7 b' import random'
 import sys
 import textwrap
 import unittest
-
-try:
-    from unittest.mock import patch
-except ImportError:
-    from mock import patch
+from unittest.mock import patch
 
 import nose.tools as nt
 from nose import SkipTest

IPython/core/tests/test_ultratb.py

@@ -7,11 +7,7 b' import os.path'
 from textwrap import dedent
 import traceback
 import unittest
-
-try:
-    from unittest import mock
-except ImportError:
-    import mock    # Python 2
+from unittest import mock
 
 from ..ultratb import ColorTB, VerboseTB, find_recursion
 

IPython/utils/tests/test_path.py

@@ -11,19 +11,12 b' import sys'
 import tempfile
 import warnings
 from contextlib import contextmanager
-
-try:  # Python 3.3+
-    from unittest.mock import patch
-except ImportError:
-    from mock import patch
-
+from unittest.mock import patch
 from os.path import join, abspath, split
 
-from nose import SkipTest
+from nose import SkipTest, with_setup
 import nose.tools as nt
 
-from nose import with_setup
-
 import IPython
 from IPython import paths
 from IPython.testing import decorators as dec