If single-value pools have a weight defined, it will be lost by this
optimization. Next time octodns-sync is run, it will show an update for
setting the weight on remote. To overcome this, this commit includes a
change to Record object that ignores the weight in single-value pools.

When debug logging is enabled, the plan() function logs lines like:

    <previous output>
    Plan: DEBUG: __init__: Creates=13, Updates=0, Deletes=0Existing=0
    <following output>

  Where a space between "Deletes=0" and "Existing=0" is missing.
  This adds it.

A quick summary of a problem with have with DNSimple provider:
Let's suppose that I have the following config:

zones:
  30.114.195.in-addr.arpa.:
    sources:
      - config
    targets:
      - dnsimple

Even if a customer has this Reverse zone configured in DNSimple, this
fails with:

400 Bad Request for url: https://api.sandbox.dnsimple.com/v2/x/domains

because it is trying to create a domain because the zone wasn't found.
octodns.provider.dnsimple.DnsimpleClientNotFound: Not found

This happens because the GET /domains endpoint at DNSimple does not
bring Reverse Zones. To make this work nice, we should use /zones/
instead making it return properly the reverse zones.

- implemented HetznerClient API class
- tested manually, lacking formal tests

Co-authored-by: Ross McFarland <ross@github.com>