Disabled the check for python code in order to reduce the runtime of 'pylearn2/scripts/papers/dropout/tests/test_dropout.py'

As suggested by nouiz , I disabled the check for python code in order to reduce the runtime to 3 hours in DEBUG_MODE.
I don,t understand how travis tests passed. This line should make it fail.

Other mode then DebugMode, check_py_code don't exist. Do you know why tests passed?