`core.getInput()` always returns a string, so testing for 'not null'
is always true. This then leads to previews set to an array with
a single empty string, breaking accept-header output.
Updated eslint rules should help avoid this issue in future, and new
integration tests verify that the github client configuration now
reflects the intended configuration options.
- Use test-specific step ids
- Remove unused input parameters
- Provide clear output on what passed or failed, including
a step summary for each passed test.
Update actions/checkout, actions/setup-node, actions/cache, and
actions/upload-artifact from v2 to v3.
Signed-off-by: Austin Vazquez <macedonv@amazon.com>
