style: remove pylint exclusions only needed for 2/3

pylintrc

@@ -84,10 +84,6 @@ disable=
 # Formatting stuff
     superfluous-parens,
     bad-continuation,
-# Disable while we still support Python 2:
-    useless-object-inheritance,
-    super-with-arguments,
-    raise-missing-from,
 # Messages that are noisy for now, eventually maybe we'll turn them on:
     invalid-name,
     protected-access,

tests/test_cmdline.py

@@ -1047,7 +1047,7 @@ def command_line(self, argv):
                 try:
                     raise Exception("oh noes!")
                 except:
-                    raise _ExceptionDuringRun(*sys.exc_info())
+                    raise _ExceptionDuringRun(*sys.exc_info()) from None
             elif argv[0] == 'internalraise':
                 raise ValueError("coverage is broken")
             elif argv[0] == 'exit':