Travis CI: Only enable C++11
Travis CI: Only enable C++11

vergil1874/InertialNav,priseborough/InertialNav,vergil1874/InertialNav,AlexHAHA/InertialNav,AlexHAHA/InertialNav,zlongshen/InertialNav,flyingk/InertialNav,flyingk/InertialNav,AlexHAHA/InertialNav,ek99800/InertialNav,priseborough/InertialNav,zlongshen/InertialNav,ek99800/InertialNav,priseborough/InertialNav,flyingk/InertialNav,flyingk/InertialNav,ek99800/InertialNav,vergil1874/InertialNav,priseborough/InertialNav,zlongshen/InertialNav