Include reversed colorscales

Author: jonmmease

packages/python/plotly/_plotly_utils/tests/validators/test_colorscale_validator.py

@@ -25,7 +25,6 @@ def validator():
     and len(c) == 2
     and isinstance(c[0], str)
     and isinstance(c[1], list)
-    and not c[0].endswith("_r")
     and not c[0].startswith("_")
 }