PEP8, documentation update, test fix

tests/modules/virtualbox/test_virtualbox_manager.py

@@ -41,4 +41,4 @@ def test_vm_non_executable_vboxmanage_path(project, manager):
     tmpfile = tempfile.NamedTemporaryFile()
     with patch("gns3server.config.Config.get_section_config", return_value={"vboxmanage_path": tmpfile.name}):
         with pytest.raises(VirtualBoxError):
-            manager.find_vboxmanage()
+            manager.find_vboxmanage()