Hi, author here.
As a user of both travis and gitlab-ci I wanted a more unified and simple deployment experience across various providers, whether it be GitHub releases, Heroku, Firebase, AWS S3...
As said rocket is the D in CI/CD: It allows to easily deploy software across a large range of providers from any CI/CD pipeline.
It does not replace your build system but instead help you to easily push your code in your various environments (dev, staging, production...).
It should be as easy as possible to use, Any feedback welcome.