Fixed errors in travis

theano/sandbox/gpuarray/fp16_help.py

 from __future__ import absolute_import, print_function, division
 
+
 def work_dtype(dtype):
     if dtype == 'float16':
         return 'float32'

theano/sparse/tests/test_type.py

 from __future__ import absolute_import, print_function, division
+
+
 def test_sparse_type():
     import theano.sparse
     # They need to be available even if scipy is not available.

theano/tensor/nnet/bn.py

-from __future__ import absolute_import, print_function, division
+from __future__ import absolute_import, print_function
 import theano
 from theano.scalar import Composite
 from theano.scalar import add, sub, true_div, mul