Travis: Use Docker to build for Linux

.travis-build.sh

@@ -44,15 +44,7 @@ fi
 
 #if OS is linux or is not set
 if [ "$TRAVIS_OS_NAME" = "linux" -o -z "$TRAVIS_OS_NAME" ]; then
-    export CC=gcc-6
-    export CXX=g++-6
-    export PKG_CONFIG_PATH=$HOME/.local/lib/pkgconfig:$PKG_CONFIG_PATH
-
-    mkdir build && cd build
-    cmake ..
-    make -j4
-
-    ctest -VV -C Release
+    docker run -v $(pwd):/citra ubuntu:16.04 /bin/bash /citra/.travis-build-docker.sh
 elif [ "$TRAVIS_OS_NAME" = "osx" ]; then
     set -o pipefail