Travis: fix the APT source for clang-3.8
Travis: fix the APT source for clang-3.8

Signed-off-by: David Wagner <60228a510f9a76940848fa2d29321fc4edfc2119@intel.com>

dawagner/parameter-framework,mgaio/parameter-framework,mgaio/parameter-framework,01org/parameter-framework,miguelgaio/parameter-framework,miguelgaio/parameter-framework,dawagner/parameter-framework,mgaio/parameter-framework,dawagner/parameter-framework,01org/parameter-framework,01org/parameter-framework,miguelgaio/parameter-framework