Important cert-manager patch release v0.5.1

[james.m...@jetstack.io]

Hey all,

We've just released the v0.5.1 patch release for cert-manager.

It contains an important fix for an issue relating to our 'retry policies' when processing an Issuer resource fails.

In some edge cases, a misconfigured client will attempt to re-verify ACME accounts at a high rate, potentially causing issues for the ACME server.

All users should upgrade to this release as soon as possible - there have been no significant or breaking changes as this is a patch release!

You can find upgrade instructions here: https://cert-manager.readthedocs.io/en/latest/admin/upgrading/index.html