chore(deps): upgrading oas-normalize to resolve validation quirks

[erunion]

🧰 Changes

• Upgrades oas-normalize to the latest version to resolve a quirk with its .validate() method where it would run dereferencing before and during validation. Since .validate() only needs to validate that's all it does now.

🧬 QA & Testing

Though the oas-normalize change was a breaking change, our use of it here doesn't need to change assuming tests still pass.

📖 Release Notes

4.0.0 (2021-08-26)

🚨  Breaking change!

.validate() will no longer dereference schemas. If you need to dereference before or after validating, you shoudl use the .deref() method instead.

• fix: stop dereferencing when running spec validation (chore(deps-dev): Bump @readme/eslint-config from 1.14.0 to 1.15.0 #153) (7b706db), closes #153
• docs: adding a pull request template (16da316)
• docs: make docs more OpenAPI friendly (chore(deps): [Security] Bump acorn from 6.4.0 to 6.4.1 #152) (68cfc34), closes #152

[kanadgupta]

LGTM other than the snapshot updates! At least that means the changes worked 🤩