[pep8] make test files and config files pep8 valid

Signed-off-by: akoskaaa <akos.hochrein@prezi.com>

tests/unit/split_buffer_test.py

@@ -3,6 +3,7 @@ from __future__ import absolute_import
 from compose.cli.utils import split_buffer
 from .. import unittest
 
+
 class SplitBufferTest(unittest.TestCase):
     def test_single_line_chunks(self):
         def reader():