companion container to create ca and certs

based on https://github.com/square/certstrap

needs .env

cp .env_skel .env

content:

SERVER_IP=<public IP>
SERVER_CA=<name of CA>
ORG=<name of Org>
ORG_UNIT=<name Org unit>

TODO:

• add as companion container to provide certs.
• doesnt generate certs if cert folder not empty. but if cert folder empty, it doesnt get added to github.
• dirty workaround: rm cert/.skel