updating for container hardening

[dandersonsw]

Changes proposed in this pull request:

• Use hardened base container image
• Add security-considerations.md file
• Update Go version
• Remove CI directory as it is not needed

Things to check

• For any logging statements, is there any chance that they could be logging sensitive data?
• Are log statements using a logging library with a logging level set? Setting a logging level means that log statements "below" that level will not be written to the output. For example, if the logging level is set to INFO and debugging statements are written with log.debug or similar, then they won't be written to the otput, which can prevent unintentional leaks of sensitive data.

Security considerations

Setting up this repo for container hardening

[markdboyd]

Why are these files being deleted?

[dandersonsw]

They are the files used by the cloudfoundry org for their pipelines, so they do not apply to us.