initial helm chart

[mcritchlow]

Fixes #301 Fixes #332

Local Checklist

• [ ] Tests written and passing locally?
• [ ] Code style checked?
• [x] QA-ed locally?
• [x] Rebased with master branch?
• [ ] Configuration updated (if needed)?
• [ ] Documentation updated (if needed)?

What does this PR do?

• Adds an initial helm chart for High Five
• Adds a dependency on the postgresql helm chart
• Adds a custom email container/service for sending app email via smtp
• Adds a custom Rancher questions.yaml file to ease deployment in Rancher
• Adds a custom networking policy which only allows the application pod to talk w/ the email pod
• Removes postfix from the Dockerfile since we're using a dedicated container/service for that now

Why are we doing this? Any context of related work?

References #301

Note: The image being used in the helm chart is in docker hub, which i build and pushed manually using docker build -t ucsdlib/hifive:stable --target production . AFTER commenting out the shibboleth setting in the production configuration file so that I could test the helm chart w/ developer authentication. Once we have google authentication working via #300 we can test that in Rancher as well.

Where should a reviewer start?

You can see this working now in Rancher: https://lib-rancher-lb.ucsd.edu/p/c-28www:p-879gn/apps

I'm going to create a separate ticket to make the k3d script work since it's useful but not directly a dependency on the context of this branch/PR

I'm also going to create a ticket to look into why the assets precompilation step needed to be moved to the entrypoint script.

Screenshots

see #301 for some screenshots on the application working, in particular the kubectl testing for the networking policy

@ucsdlib/developers - please review

[coveralls]

Coverage remained the same at 99.66% when pulling 42787d2b30e44843f50b1c3f06db6b099459aae3 on init-helm-chart into aee8d15e07f83308728fa79c8f83f8c6ec3d1a0b on master.