[Infrastructure] Migrate testing to another platform

[Chalarangelo]

As of March 2021, Travis CI's credits are all dried up. We can either move to Circle CI or check GitHub Actions as an alternative. While our tests still run locally, we might run into a few issues here and there, namely with auto deployment from Travis, but that should not be a major problem for the time being.

[Chalarangelo]

Migrated testing to GitHub actions. Cypress tests will be deprecated soon, so they are not running on the current workflow.