Use uuid4 instead of uuid1 to generate trace uid (#1236)

* Use uuid4 instead of uuid1 to generate trace uid

Author: erichiggins

_plotly_utils/basevalidators.py

@@ -2298,7 +2298,7 @@ def validate_coerce(self, v, skip_invalid=False):
             # Set new UIDs
             if self.set_uid:
                 for trace in v:
-                    trace.uid = str(uuid.uuid1())
+                    trace.uid = str(uuid.uuid4())
 
         else:
             if skip_invalid: