Release v3.17.0

[Tom Limoncelli]

https://github.com/StackExchange/dnscontrol/releases/tag/v3.17.0

This release includes many new features and bug fixes:

Some highlights:

* An elusive bug in CLOUDFLAREAPI was fixed (#1543) related to TXT records and quoting. The SPF Optimizer may have installed additional quotes in your TXT records years ago. This went unnoticed because CloudFlare stripped these quotes silently. DNSControl will fix your TXT records on the next run.

* `--creds !command` now accepts an entire command line, not just the filename of a script.  This works on both Unix-like and Windows (PowerShell) systems, thus a command like `dnscontrol preview --creds "!op inject -i creds.json.tpl"` will work on both. See https://stackexchange.github.io/dnscontrol/creds-json.html

* CSCGLOBAL now has experimental support as a DNS Service Provider (DSP). Previously it was only a Registrar. Sadly the API locks any zone for 5-7 minutes after any changes, which could cause timeouts in CI/CD pipelines.

* Docker users rejoice!  The Dockerfile has been greatly improved.

* Welcome Riyadh Al Nur (@riyadhalnur) as the new maintainer of the Google DNS (GCLOUD) provider!  Thanks for stepping up!

Thanks to all the volunteers for their contributions: Jan-Philipp Benecke, F.D.Castel, Riyadh Al Nur, Chris, Nicolas Lorin. (apologies if I missed anyone)


## Breaking changes:

* n/a

## Major features:

* NEW PROVIDER: CSCGLOBAL as DNS Service Provider (#1516) (experimental)
* FEATURE: --creds can refer to a command line to execute in addition to a file or script (#1521)
* MAINT: New Dockerfile (fix #1459) (#1537)
* GCLOUD: Welcome riyadhalnur as the new owner for GCLOUD (#1525)

## Provider-specific changes:

* CLOUDFLAREAPI: Fix TXT quoting bug (#1538) (#1543)
* GANDI: DOCS: Document sharing_id errors (#1542)
* CSCGLOBAL: Enable CAA records (#1536)
* VULTR: Enable long TXT (#1518)

## Other changes and improvements:

* MAINT: Unify provider outputs to pkg/printer (#1546)
* MAINT: Enforcing formatted code (#1544)
* MAINT: Put some target-related warnings behind a flag (#1541)
* CLOUDFLAREAPI: FIX: Preventing segfault when Cloudflare API limit is reached (#1530)
* NEW FEATURE: Add deprecation notice to create-domains command (#1529)
* CHORE: update provider maintainer message (#1526)
* MAINT: docker: Add CA certificates to Docker image (#1523)
* MAINT: Bump github.com/tdewolff/minify/v2 from 2.11.5 to 2.11.7 (#1520)
* SOFTLAYER: Bump github.com/softlayer/softlayer-go from 1.0.4 to 1.0.5 (#1519)

## Depreciation warnings

* **Call for new volunteer maintainers for NAMEDOTCOM, and SOFTLAYER.** These providers have no maintainer.   Maintainers respond to PRs and fix bugs in a timely manner, and try to stay on top of protocol changes.
* **ACME/Let's Encrypt support is frozen and will be removed after December 31, 2022.**  The `get-certs`      command (renews certs via Let's Encrypt) has no maintainer. There are other projects that do a better job. If you don't use this feature, please do not start. If you do use this feature, please plan on migrating to      something else.  See discussion in https://github.com/StackExchange/dnscontrol/issues/1400
* **convertzone is frozen and will be removed after June 30, 2022.** The `convertzone` stand-alone program is replaced by the `get-zone` subcommand of DNSControl. It does everything `convertzone` did and more.
* **Provider ACTIVEDIRECTORY_PS is frozen and will be removed after June 30, 2022.** It is replaced by MSDNS  which is 100% feature compatible and works better. (We believe nobody uses it.)
* **get-zones syntax changes in v3.16** Starting in v3.16, the command line arguments for `dnscontrol get-    zones` changes. For backwards compatibility change `provider` to `-`. See documentation for details.