Fix Kaleido version to work around release error (#1109)

Pin the Kaleido version to work around bad release

Kaleido doesn't work with package managers like Poetry.  It also hasn't
seen a release in 2 years and the package manager seems to have
forgotten about it. Therefore, pin the kaleido version to solve
plotly/Kaleido#156.

Co-authored-by: Setepenre <pierre.delaunay.tr@gmail.com>

setup.py

@@ -157,7 +157,8 @@
         "tabulate",
         "AppDirs",
         "plotly",
-        "kaleido",
+        # Pin the version to work around https://github.com/plotly/Kaleido/issues/156.
+        "kaleido==0.2.1",
         "requests",
         "pandas",
         "gunicorn",