build config: fix parameter configuration for docker-compose

We were incorrectly using clang all the time, overriding gcc.
This also brings newer version of docker-compose.

Signed-off-by: Nicolas Oliver <dario.n.oliver@intel.com>
Signed-off-by: Alex Tereschenko <alext.mkrs@gmail.com>

.travis.yml

@@ -45,6 +45,12 @@ matrix:
 services:
   - docker
 
+before_install:
+  - sudo rm /usr/local/bin/docker-compose
+  - curl -L https://github.com/docker/compose/releases/download/1.9.0/docker-compose-`uname -s`-`uname -m` > docker-compose
+  - chmod +x docker-compose
+  - sudo mv docker-compose /usr/local/bin
+
 before_script:
   - if [ "$CC" == "gcc" ]; then export CC=gcc-4.8; fi
   - if [ "$CXX" == "g++" ]; then export CXX=g++-4.8; fi