Add basic support for v14

[rnestler]

So the goal is to have an implementation which can serialize and deserialize v0.13, v14 and mixed implementations which provides compatibility for both. This means we need to make fields optional which were removed in v14 or were not present in v0.13.

Checklist

• Tests added if applicable
• README updated if applicable
• CHANGELOG updated if applicable
• If a commit includes a breaking change, include the string [breaking-change] somewhere in the commit message

[dbrgn]

Version 14 was now officially released! https://github.com/SpaceApi/schema/blob/master/CHANGELOG.md

[rnestler]

@dbrgn This just adds the most minimal v14 support, by just adding the api_compatibility field and supporting both v0.13, v14 or a mixed serialization. I suggest we merge it anyways and add the other stuff as we go 🙂

[dbrgn]

Nice! I like the approach.

Could you add a test for the v14 constructor?

[dbrgn]

Does a default impl for the version make sense? I'd rather remove the Default derive from StatusBuilder.

[rnestler]

Well it would make constructing StatusBuilder a lot more annoying since one would need to specify all the fields (see new(), v0_13(), v14() currently line 273.
If we remove Default I'd also remove the new constructor.

[dbrgn]

Yeah, true. But from a user perspective, as long as we use the constructor methods, it shouldn't be an issue, right?

[rnestler]

Could you add a test for the v14 constructor?

Added a test for the v14 and mixed builder.

[dbrgn]

Let's merge this with Default support for now!