title: 'Package' object has no attribute 'level' when inheriting logging.Logger
body: <p>I'm trying to create a custom class called <code>Package</code> that has logging capabilities.</p>
  
  <pre><code>import logging
  
  logger = logging.getLogger('console')
  
  class Package(logging.Logger):
      def __enter__(self):
          return self
      def __exit__(self,exc_type,exc_val,exc_tb):
          pass
      def __init__(self,**kwargs):
          pass
  
  with Package() as p:
      p.error('test')
  </code></pre>
  
  <p>For some reason I get this error message when I use any of the logging functions:</p>
  
  <pre><code>Traceback (most recent call last):
    File "test.py", line 14, in &lt;module&gt;
      p.error('test')
    File "C:\Program Files\Python36\lib\logging\__init__.py", line 1334, in error
      if self.isEnabledFor(ERROR):
    File "C:\Program Files\Python36\lib\logging\__init__.py", line 1548, in isEnabledFor
      return level &gt;= self.getEffectiveLevel()
    File "C:\Program Files\Python36\lib\logging\__init__.py", line 1537, in getEffectiveLevel
      if logger.level:
  AttributeError: 'Package' object has no attribute 'level'
  </code></pre>