Google Assured Open Source Software

This is more of an FYI, Google has added several of our libraries to their [Assured Open Source Software](https://cloud.google.com/assured-open-source-software) list, and are running security fuzzing [checks](https://github.com/google/oss-fuzz/tree/master/projects) against `ipython`, `ipykernel`, `nbconvert` and `jupyter_server`.