Reformat code using black

Segments where readability was hampered were fixed by appropriate
format skipping directives. New code should hopefully be black
compatible. The moment they remove the -S option is probably the moment
I stop using black though.

discord/mixins.py

@@ -27,6 +27,7 @@ __all__ = (
     'Hashable',
 )
 
+
 class EqualityComparable:
     __slots__ = ()
 
@@ -40,6 +41,7 @@ class EqualityComparable:
             return other.id != self.id
         return True
 
+
 class Hashable(EqualityComparable):
     __slots__ = ()