While appveyor supports a [skip appveyor] you cannot skip only travis. What is the feeling about adding e.g. https://github.com/travis-ci/travis-ci/issues/5032#issuecomment-273626567 to our build. We could also do some simple kind of change detection that we don't build the C++/Python parts and only Java and the integration tests if there was a change in the PR that only affects Java.
I think it might be worthwhile to spend a bit on that to get a bit of load of the CI infrastructure.