fix flake8 'd3viz/tests/*py'

theano/d3viz/tests/test_d3viz.py

-from nose.plugins.skip import SkipTest
-
-from theano.d3viz.formatting import pydot_imported
-if not pydot_imported:
-    raise SkipTest('Missing requirements')
-
 import numpy as np
 import os.path as pt
 import tempfile
@@ -14,6 +8,11 @@ import theano as th
 import theano.d3viz as d3v
 from theano.d3viz.tests import models
 
+from nose.plugins.skip import SkipTest
+from theano.d3viz.formatting import pydot_imported
+if not pydot_imported:
+    raise SkipTest('Missing requirements')
+
 
 class TestD3Viz(unittest.TestCase):
 

theano/d3viz/tests/test_formatting.py

-from nose.plugins.skip import SkipTest
-
-from theano.d3viz.formatting import pydot_imported
-if not pydot_imported:
-    raise SkipTest('Missing requirements')
-
 import numpy as np
 import unittest
 
@@ -11,6 +5,11 @@ import theano as th
 from theano.d3viz.formatting import PyDotFormatter
 from theano.d3viz.tests import models
 
+from nose.plugins.skip import SkipTest
+from theano.d3viz.formatting import pydot_imported
+if not pydot_imported:
+    raise SkipTest('Missing requirements')
+
 
 class TestPyDotFormatter(unittest.TestCase):
 

theano/tests/test_flake8.py

@@ -176,9 +176,7 @@ whitelist_flake8 = [
     "gof/unify.py",
     "gof/__init__.py",
     "gof/sandbox/equilibrium.py",
-    "d3viz/__init__.py",
-    "d3viz/tests/test_d3viz.py",
-    "d3viz/tests/test_formatting.py"
+    "d3viz/__init__.py"
 ]