Autocert: respect federation root bundles

[sourishkrout]

What would you like to be added

Deploy federation bundles alongside root CA bundle and leaf certificate into containers. Both for first cert enrollment and successive cert renewals.

Why this is needed

step already supports federation and autocert users should have the ability to take advantage of connecting across federated roots.

[Sadzeih]

Is there any news on this? I really want to use federation and autocert together to link my CAs in my k8s clusters.

[dopey]

Notes:

Have the sidecar run step ca federate

[dopey]

https://github.com/smallstep/autocert/blob/master/bootstrapper/bootstrapper.sh#L12