Feat: Migrate to Github Actions

[faisalill]

What's Changed:

Replace travis.yml with similar .github/workflows/tests.yml file.

Test Plans:

Opening a PR triggers tests: Github Actions Test: https://github.com/faisalill/cache/pull/1 Travis Tests: https://app.travis-ci.com/github/utopia-php/cache/builds/259056517 Both have the same result.

Mention/Reference:

https://github.com/utopia-php/framework/issues/103