I don’t know anything about SBT, but jasmine-reporters has JUnit reporters that work with both Jasmine1.x and Jasmine2.x. Looking at the above pull request, it seems it was just a simple port of the JUnit reporter from jasmine-reporters into SBT with a very (very) little bit of glue to make it available inside the plugin’s jasmine environment.
If someone hasn’t already done it, I suspect it would be fairly straightforward to include the runner from jasmine-reporters as the pull request above did two years ago.
Good luck.
Ben