Fix travis
diff --git a/tests/memdbg.py b/tests/memdbg.py
index 324d0fd..0deeb9e 100644
--- a/tests/memdbg.py
+++ b/tests/memdbg.py
@@ -18,7 +18,7 @@
     int backtrace(void **buffer, int size);
     char **backtrace_symbols(void *const *buffer, int size);
     void backtrace_symbols_fd(void *const *buffer, int size, int fd);
-    """)
+    """)  # noqa
 _api = _ffi.verify(
     """
     #include <openssl/crypto.h>
@@ -29,10 +29,12 @@
 
 verbose = False
 
+
 def log(s):
     if verbose:
         print(s)
 
+
 def _backtrace():
     buf = _ffi.new("void*[]", 64)
     result = _api.backtrace(buf, len(buf))