Letsencrypt could makes symlinks to standard locations in the future.

It was responsible for

    [CRITICAL] Rendering SLS 'base:salt.minion.cert' failed: Jinja variable 'dict object' has no attribute 'cfg01.mk20-lab-advanced.local'
    [ERROR   ] Data passed to highstate outputter is not a valid highstate return: {'local': ["Rendering SLS 'base:salt.minion.cert' failed: Jinja variable 'dict object' has no attribute 'cfg01.mk20-lab-advanced.local'"]}

- allow defining custom key/cert path
- ensure key/cert directories
- set key/cert permissions by metadata

source:engine metadata created - defaults to pkg
installation, pip installation alternative added