Update setup.py

Author: LiamConnors

packages/python/plotly/setup.py

@@ -420,7 +420,7 @@ def run(self):
 
         # update plotly.js version in _plotlyjs_version
         rev = build_info["vcs_revision"]
-        date = build_info["committer_date"]
+        date = str(build_info["committer_date"])
         version = "_".join([self.devrepo, self.devbranch, date[:10], rev[:8]])
         overwrite_plotlyjs_version_file(version)