Bump notebook from 5.7.6 to 6.4.12 in /TrackingNtuples/scripts

Bumps [notebook](http://jupyter.org) from 5.7.6 to 6.4.12.

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

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

Author: dependabot[bot]

TrackingNtuples/scripts/mlenv-requirements.txt

@@ -46,7 +46,7 @@ nbconvert==5.4.1
 nbdime==1.0.5
 nbformat==4.4.0
 networkx==2.2
-notebook==5.7.6
+notebook==6.4.12
 numpy==1.16.2
 pandas==0.24.1
 pandocfilters==1.4.2

TrackingNtuples/scripts/venv-requirements.txt

@@ -46,7 +46,7 @@ mock==2.0.0
 msgpack==0.6.1
 nbconvert==5.4.0
 nbformat==4.4.0
-notebook==5.7.2
+notebook==6.4.12
 numpy==1.15.4
 pandas==0.23.4
 pandocfilters==1.4.2