message: test also clang support
diff: @@ -3,7 +3,9 @@ dist: trusty
  git:
  submodules: true
  language: c
  -compiler: gcc
  +compiler:
  + - clang
  + - gcc
  before_install:
  - echo "deb https://dl.bintray.com/rwth-os/hermitcore vivid main" | sudo tee -a /etc/apt/sources.list
  - travis_retry sudo apt-get -qq update
  