certmanager

[djthorpe]

• Create a certmanager handler
• Should be able to create a CA
• Should be able to import a CA
• Should be able to query and delete a CA. CA should not be deletable if there are certs which are signed by it
• Should be able to create a new cert from a CA
• Should be able to query, renew, export and delete a cert

Integrate certs into nginx
Add Let's Encrypt cert generation
Create an API client for interacting with the cert manager