A good thing to note here is that Travis CI is really great for running custom build scripts, but it is not a platform like Jenkins, where it is able to do everything itself with plugins. You're free to put all your build logic in scripts, Gradle/NPM/whatever-build-tool commands, and just tell Travis what you need it to do. So Travis itself is quite simple to get up and running, because it is just the commands you're already doing to build and deploy your project, just in script form.
A good thing to note here is that Travis CI is really great for running custom build scripts, but it is not a platform like Jenkins, where it is able to do everything itself with plugins. You're free to put all your build logic in scripts, Gradle/NPM/whatever-build-tool commands, and just tell Travis what you need it to do. So Travis itself is quite simple to get up and running, because it is just the commands you're already doing to build and deploy your project, just in script form.
Sounds good, I’m using Gradle and I’m pretty happy with it.