Revert "[core] configure the root logger (#536)" (#556)

This reverts commit 07a6e93.

Author: Emanuele Palazzetti

ddtrace/__init__.py

@@ -1,4 +1,3 @@
-import logging
 from .monkey import patch, patch_all
 from .pin import Pin
 from .span import Span
@@ -7,10 +6,6 @@
 
 __version__ = '0.13.0'
 
-# configure the root logger
-logging.basicConfig()
-log = logging.getLogger(__name__)
-
 # a global tracer instance with integration settings
 tracer = Tracer()
 config = Config()