Update helm chart + docker image

[ml8]

For our JupyterHub version, we are on 1.1.1 and the current version is 1.1.3. It doesn't look like there have been many important changes (CHANGELOG), but we might want to just stay current, or update to 1.1.4 if it is pushed over winter break.

We should also rebuild our Docker image in order to pick up any updates to packages that we pip install. Since the image is built and then is immutable, we don't upgrade these packages unless we rebuild.

As part of this, we should also see if anyone wants to add any pre-installed packages (do this as part of #30 ).

@anesepark @walidabualafia

[ml8]

Fixed by #34