[travis] Removed llvm toolchain for now
[travis] Removed llvm toolchain for now

ScazLab/baxter_collaboration,ScazLab/baxter_collaboration,ScazLab/baxter_collaboration,ScazLab/human_robot_collaboration,ScazLab/baxter_collaboration,ScazLab/human_robot_collaboration,ScazLab/human_robot_collaboration,ScazLab/human_robot_collaboration