Release v0.3.1

Changed

• README

  • Replace linters list with version table to act as a quick reference

• Go versions

  • Update go-ci-stable from 1.15.5 to 1.15.6
  • Update go-ci-oldstable from 1.14.12 to 1.14.13
  • Update go-ci-unstable from 1.15.5 to 1.15.6
    • the plan is to swap out to the next unstable Go version when it becomes
      available
  • Update go-ci-stable-debian-build from 1.15.5 to 1.15.6
  • Update go-ci-stable-alpine-buildx86 from1.15.5-alpine3.12 to
    1.15.6-alpine3.12
  • Update go-ci-stable-alpine-buildx64 from 1.15.5-alpine3.12 to
    1.15.6-alpine3.12

NOTE: The go-ci-lint-only image is not updated in this release. We're
waiting on a new upstream release.

Fixed

• Replace orijtech/httperroryzer pseudo-version with equivalent tag

• Dependabot: Invalid ignore condition (version range) specified for
  "oldstable" image

References

• See the v0.3.1 milestone for the issues associated with this release.
• See our CHANGELOG for more information.