Fix warnings produced by new pylint versions

Author: barisione

tests/mixin_scripts_repo.py

@@ -29,7 +29,8 @@ def setUp(self):
         assert not self.repo
         assert not self.scripts_dir
 
-        self.repo = self.config_repo()
+        # This class's config_repo doesn't return, but the derived ones do.
+        self.repo = self.config_repo() # pylint: disable=assignment-from-no-return
 
         assert self.repo
 

tests/testutils.py

@@ -19,7 +19,7 @@ def makedirs(dir_path):
             raise
 
 
-class WorkDir(object):
+class WorkDir():
     '''
     Temporarily change the current working directory.
 
@@ -53,7 +53,7 @@ def __exit__(self, exception_type, exception_value, traceback):
         self._old_work_dir = None
 
 
-class EnvAdder(object):
+class EnvAdder():
     '''
     Add a directory to `$PATH`.