travis-ci uses old gcc 4.6, which doesn't support -std=c++11
$ export CXX=g++
$ export CC=gcc
$ git clone --depth=50 --branch=master git://github.com/arne-cl/alt-mulig.git arne-cl/alt-mulig
$ cd arne-cl/alt-mulig
$ git checkout -qf eaa28322ccda8c17d70b16a1b8981ff4ed70abff
$ gcc --version
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
$ make
g++ -std=c++11 cpp/cfg-test.cpp -o cfg-test
cc1plus: error: unrecognized command line option ‘-std=c++11’
make: *** [all] Error 1