* Use local copies of pebble certs as docker image contains outdated versions
* Update the preferred chain used in Staging
* Put test API keys in github secrets, add code to create/delete test domains to prevent misuse
* Simplify dns_add_acmedns

- Updated 6 Dockerfiles to use JSON array syntax for CMD
- Skip CNAME authoritative check if it fails
- Skip another authoritative check to fix flaky tests

* Fix execute permissions for dns scripts
* Send the profile with the order request
* Update chown command for all alpine based Dockerfiles
* Rewrote the profiles parsing code to be more generic and more readable
* Change some tests which depend on DNS to be warning instead of failure to prevent false alerts
* Skip some ftp tests on centos6 and centos7, setup issue with vsftpd

Fix passive ftp command

Force new certificate if key alg changes (fixes #276)

Reduce test noise