Fix logging

- Following advice here: https://docs.python.org/3/howto/logging.html#configuring-logging-for-a-library
- Renamed the logger: client -> fbchat
- Remove logging_level init parameter from Client
- Use print instead of log.info in examples

fbchat/_core.py

@@ -1,7 +1,7 @@
 import logging
 import aenum
 
-log = logging.getLogger("client")
+log = logging.getLogger("fbchat")
 
 
 class Enum(aenum.Enum):