try to fix mypy errors in logging

mu_map/logging.py

 import argparse
 import datetime
 import logging
-import logging.handlers
+from logging import Formatter, getLogger, StreamHandler
+from logging.handlers import WatchedFileHandler
 import os
 import shutil
 from typing import Dict, Optional
 
 
-FORMATTER = logging.Formatter(
+FORMATTER = Formatter(
     fmt="%(asctime)s - %(levelname)s: %(message)s", datefmt="%m/%d/%Y %I:%M:%S"
 )
 
@@ -47,19 +48,19 @@ def rotate_log_file(filename: str):
 
 
 def get_logger(logfile: Optional[str] = None, loglevel: Optional[str] = None):
-    logger = logging.getLogger()
+    logger = getLogger()
 
     if loglevel:
         _level = getattr(logging, loglevel)
         logger.setLevel(_level)
 
-    _handler = logging.StreamHandler()
+    _handler = StreamHandler()
     _handler.setFormatter(FORMATTER)
     logger.addHandler(_handler)
 
     if logfile:
         rotate_log_file(logfile)
-        _handler = logging.handlers.WatchedFileHandler(logfile)
+        _handler = WatchedFileHandler(logfile)
         _handler.setFormatter(FORMATTER)
         logger.addHandler(_handler)
 
@@ -81,4 +82,4 @@ if __name__ == "__main__":
     logger.info("This is a test!")
     logger.warning("The training loss is over 9000!")
     logger.error("This is an error")
-    logger.info("The end")
+    logger.debug("The end")