How to run Selenium Server on Travis CI when testing a Node.js project with Nightwatch

I have a node.js project that I am trying to use Nightwatch to test. Nightwatch uses selenium-server under-the-hood.

My tests work correctly locally, but on Travis it immediately chokes with this error:

There was an error while starting the Selenium server:

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/openqa/grid/selenium/GridLauncherV3 : Unsupported major.minor version 52.0

I think that means that it wants Java 8 or newer, but I'm not sure how to set that up on Travis. I tried setting jdk: oracle8jdk in my travis.yml, but that didn't seem to make a difference.

Any suggestions?

via Nathan Friedly