Add Github Action CI/CD integrations tests to PR flow using pre-existing tests at `make integration`

[aaron-prindle]

Currently when a PR is submitted to container-diff the integration tests container-diff has are not run against the PR. Something like the tests here: https://github.com/GoogleContainerTools/container-diff/blob/master/.travis.yml

should be added back to the project as github actions (eg: something like .github/worksflows/integration-tests.yaml)