Acme unable to replace a staging cert after testing

[jeffclay]

Is your feature request related to a problem? Please describe.
After creating a certificate using test_cert flag then removing the flag, the result was nothing happening due to:

1. Acme state does a check to see if cert exists and if it does it just checks if it needs renewed. No consideration for replacing a staging certificate.

   salt/salt/states/acme.py

   Line 104 in 75269c4

   if not __salt__["acme.has"](certname):

2. Acme module does not have capability to revoke or delete a certificate.

Describe the solution you'd like
Option to specify that the existing staging/test cert should be replaced with a production cert.

Describe alternatives you've considered
Manually invoking certbot commands.