[chore] Improve address verification unit tests

[nwithan8]

Description

See EasyPost/easypost-csharp#540 for more details.

• Update examples submodule for new "incorrect address" fixture
• Update address verification unit tests to better test target functionality

Testing

• Update unit tests, re-record cassettes as needed
• Update CI to match other libraries (run unit tests in all Node versions, run linting and coverage analysis only in the latest Node version)

Pull Request Type

Please select the option(s) that are relevant to this PR.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Improvement (fixing a typo, updating readme, renaming a variable name, etc)

[nwithan8]

CI is failing on Node 12, seems to be an issue with an npm package used for coverage:

Run EASYPOST_TEST_API_KEY=123 EASYPOST_PROD_API_KEY=123 make coverage
npm run coverage

> @easypost/[email protected] coverage /home/runner/work/easypost-node/easypost-node
> cross-env NODE_ENV=test nyc npm run test

Unexpected token '?'
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! @easypost/[email protected] coverage: `cross-env NODE_ENV=test nyc npm run test`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the @easypost/[email protected] coverage script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/runner/.npm/_logs/202[4](https://github.com/EasyPost/easypost-node/actions/runs/7452210211/job/20275123483?pr=430#step:7:5)-01-08T19_28_24_20[5](https://github.com/EasyPost/easypost-node/actions/runs/7452210211/job/20275123483?pr=430#step:7:6)Z-debug.log
make: *** [Makefile:[15](https://github.com/EasyPost/easypost-node/actions/runs/7452210211/job/20275123483?pr=430#step:7:16): coverage] Error 1
Error: Process completed with exit code 2.

Can't seem to re-create locally with the same environment:

UPDATE: It's Chai using syntax that only exists in Node 14+: chaijs/chai#1553 (comment)

✖ ERROR: /home/runner/work/easypost-node/easypost-node/node_modules/chai/lib/chai/assertion.js:69
    flag(this, 'eql', config.deepEqual ?? util.eql);