Fix python 3 compatibility, PEP8 issue.

dulwich/tests/test_line_ending.py

@@ -62,6 +62,7 @@ class LineEndingConversion(TestCase):
 
 
 class GetLineEndingAutocrlfFilters(TestCase):
+
     def test_get_checkin_filter_autocrlf_default(self):
         checkin_filter = get_checkin_filter_autocrlf(b"false")
 

dulwich/tests/test_refs.py

@@ -345,7 +345,7 @@ class DiskRefsContainerTests(RefsContainerTests, TestCase):
             b'refs/some/ref/sub', b'42d06bd4b77fed026b154d16493e5deab78f02ec')
 
     def test_setitem_packed(self):
-        with open(os.path.join(self._refs.path, 'packed-refs'), 'w') as f:
+        with open(os.path.join(self._refs.path, b'packed-refs'), 'w') as f:
             f.write('# pack-refs with: peeled fully-peeled sorted \n')
             f.write(
                 '42d06bd4b77fed026b154d16493e5deab78f02ec refs/heads/packed\n')