Flake8 fixes.

theano/configparser.py

@@ -15,7 +15,6 @@ from six import StringIO
 import theano
 from theano.compat import configparser as ConfigParser
 from six import string_types
-import collections
 
 _logger = logging.getLogger('theano.configparser')
 

theano/tests/test_flake8.py

@@ -197,7 +197,6 @@ whitelist_flake8 = [
     "sandbox/linalg/ops.py",
     "sandbox/linalg/__init__.py",
     "sandbox/linalg/tests/test_linalg.py",
-    "sandbox/gpuarray/comp.py",
     "sandbox/gpuarray/basic_ops.py",
     "sandbox/gpuarray/nnet.py",
     "sandbox/gpuarray/subtensor.py",