FIX: Trying to fix CI

.gitlab-ci.yml

 image: debian:latest
 
 before_script:
+    - echo "deb http://ftp.us.debian.org/debian unstable main contrib non-free" >> /etc/apt/sources.list.d/unstable.list
     - apt-get update
-    - apt-get install -y -qq make cmake libboost-test-dev gcc-5
+    - apt-get install -y -t unstable gcc-5
+    - apt-get install -y -qq make cmake libboost-test-dev
     - ./build.sh
 
 run_tests: