You do not need to subscribe to Saucelabs. You can customize your Travis CI build with Virtual Framebuffer to simulate the display.
You need to add the following to your .travis.yml:
before_script: - "export DISPLAY=:99.0" - "sh -e /etc/init.d/xvfb start" - sleep 3
Firefox is installed in all Travis CI containers, so you only need to start the web server after that in the before_script section, which will launch your application, and then you can run Protractor tests.
For more information, you can check this: https://docs.travis-ci.com/user/gui-and-headless-browsers/#Using-xvfb-to-Run-Tests-That-Require-a-GUI
source share