message: travis.yml: Fix libfranka branch name fallback
diff: @@ -10,7 +10,7 @@ before_script:
  cd ~/workspace
  git clone https://github.com/frankaemika/libfranka.git
  cd libfranka
  - git checkout ${TRAVIS_PULL_REQUEST_BRANCH:-TRAVIS_BRANCH} || git checkout master
  + git checkout ${TRAVIS_PULL_REQUEST_BRANCH:-${TRAVIS_BRANCH}} || git checkout develop
  git submodule update --init --recursive
  - |
  cd ~/workspace
  