Fix feature_gates

[nicokratky]

Hi!

feature_gates and runtime_config are still broken.

The feature_gates map also had the same problem with the expected type as the runtime_config had. I also had to initialize the RuntimeConfig and FeatureGates maps of the kind resource, as otherwise go would complain about an assignment to an entry in a nil map.
The test cases were also wrong, as you changed the types of those two options to maps.

Feel free to edit/ask for any changes 😊

[tehcyx]

Great work, thanks. I had thought I covered it all. Running my tests again. And seems I also have to do some more fixes on PR tester...

[tehcyx]

Huh, I was not aware the test syntax is different for the map. TIL!

Btw if you have a suggestion to improve this part: https://github.com/tehcyx/terraform-provider-kind/blob/master/kind/structure_kind_config.go#LL47C16-L47C26

I'm not sure this is the best solution. I was hoping that with a map I could have a "api/alpha" key that is a string, but it seems HCL does not allow that.

[tehcyx]

Ran your code locally and it seems to be working fine. I also fixed the PR test runner (again) for the next PR to come in.

[nicokratky]

Hey! Thanks for merging this so quickly!

Btw if you have a suggestion to improve this part: https://github.com/tehcyx/terraform-provider-kind/blob/master/kind/structure_kind_config.go#LL47C16-L47C26

I think that your solution is actually quite okay, that's a pretty unfortunate limitation of HCL in this case. My only recommendation would be to document this behavior, as it is not trivial that your provider will replace certain characters.