StreamHandler.__repr__: ensure that stream.name is a string

This fixes a TypeError in case the `name` is a integer.

Ref: pytest-dev/pytest#2555

Lib/logging/__init__.py

@@ -999,7 +999,7 @@ def emit(self, record):
 
     def __repr__(self):
         level = getLevelName(self.level)
-        name = getattr(self.stream, 'name', '')
+        name = str(getattr(self.stream, 'name', ''))
         if name:
             name += ' '
         return '<%s %s(%s)>' % (self.__class__.__name__, name, level)