Bump notebook in /attic/s2i-notebook-image_old/minimal-notebook

Bumps [notebook](http://jupyter.org) from 5.7.8 to 6.4.10.

---
updated-dependencies:
- dependency-name: notebook
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

attic/s2i-notebook-image_old/minimal-notebook/requirements.txt

@@ -1,4 +1,4 @@
-notebook==5.7.8
+notebook==6.4.10
 jupyterhub==0.9.6;python_version>"2.7"
 jupyterlab==0.35.6;python_version>"2.7"
 jupyter_kernel_gateway==2.3.0