Set versioning pattern to earlySemver versioning in sbt

[zainab-ali]

This issue was copied over from: https://github.com/disneystreaming/weaver-test/issues/253
It was opened by: Baccata

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to help downstream users ... but also after we assess how much of a pain it'll be to try to guarantee backward compat

[zainab-ali]

This comment was copied over from: https://github.com/disneystreaming/weaver-test/issues/253#issuecomment-824280476
It was written by: keynmol

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I think this would be a good opportunity to lock down some of the internal-ish traits that we have exposed.

The only argument against that I can see is keeping integration points open (*Aux classes and unsealed TestOutcome), the rest of the hierarchy can be probably locked down.