Merge pull request #104 from yy/dependabot/pip/tornado-6.5.1

Bump tornado from 6.4.2 to 6.5.1

Author: yy

requirements.txt

@@ -566,7 +566,7 @@ toolz==0.12.1
     #   dask
     #   datashader
     #   partd
-tornado==6.4.2
+tornado==6.5.1
     # via
     #   bokeh
     #   ipykernel