Remove root logger usage (#1617)

The logging root logger was used in the utils which can cause noise when
inspecting logs. Properly defining a logger and using it as is done
everywhere increase consistency to the overall codebase.

Co-authored-by: olaure <o.s.c.l.a.u.r.e.nt@gmail.com>

rq/utils.py

@@ -22,6 +22,7 @@ from redis.exceptions import ResponseError
 from .compat import as_text, is_python_version, string_types
 from .exceptions import TimeoutFormatError
 
+logger = logging.getLogger(__name__)
 
 class _Colorizer:
     def __init__(self):
@@ -141,7 +142,7 @@ def import_attribute(name):
             module = importlib.import_module(module_name)
             break
         except ImportError:
-            logging.warning("Import error for '%s'" % module_name, exc_info=True)
+            logger.warning("Import error for '%s'" % module_name, exc_info=True)
             attribute_bits.insert(0, module_name_bits.pop())
 
     if module is None: