[BUG] Change logging config (#307)

* Change logging config.

* Some adjusts.

* Remove a code smell.

Author: moromimay

butterfree/__init__.py

@@ -1,8 +1 @@
 """Module docstring example, following Google's docstring style."""
-import logging.config
-import os
-import sys
-
-sys.path.insert(0, os.path.abspath("."))
-
-logging.config.fileConfig(fname="butterfree/logging.conf")