pytest: Add a skip mark for use with bdd.

pytest.ini

@@ -11,6 +11,7 @@ markers =
     not_xvfb: Tests which can't be run with Xvfb.
     frozen: Tests which can only be run if sys.frozen is True.
     integration: Tests which test a bigger portion of code, run without coverage.
+    skip: Always skipped test.
 flakes-ignore =
     UnusedImport
     UnusedVariable

tests/conftest.py

@@ -62,6 +62,7 @@ def _apply_platform_markers(item):
             "Can only run when frozen"),
         ('not_xvfb', item.config.xvfb_display is not None,
             "Can't be run with Xvfb."),
+        ('skip', True, "Always skipped."),
     ]
 
     for searched_marker, condition, default_reason in markers: