[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

src/pyhf/futures.py

@@ -12,7 +12,7 @@ class TrivialExecutor(futures.Executor):
     """
 
     def __repr__(self):
-        """ Representation of the object """
+        """Representation of the object"""
         module = type(self).__module__
         qualname = type(self).__qualname__
         return f"<{module}.{qualname} object at {hex(id(self))}>"