Upgrade to go 1.17

[genevieveluyt]

Description

Basically just a copy of https://github.com/Shopify/kubeaudit/pull/382 with requested changes applied because we didn't get any response for a while...

Upgrading to 1.17 should fix the k8s-related Dependabot PRs (such as https://github.com/Shopify/kubeaudit/pull/403) that are currently failing (I tried locally).

Type of change

• [ ] Bug fix :bug:
• [ ] New feature :sparkles:
• [ ] This change requires a documentation update :book:
• [ ] Breaking changes :warning:

  How Has This Been Tested?

• [ ] Test A
• [ ] Test B

Checklist:

• [ ] I have :tophat: my changes (A 🎩 specifically includes pulling down changes, setting them up, and manually testing the changed features and potential side effects to make sure nothing is broken)
• [ ] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] The test coverage did not decrease
• [ ] I have signed the appropriate Contributor License Agreement