Improve travis.yml readability
Improve travis.yml readability

Also fix problem with log files over 4M causing build failure

CornerOfSkyline/qgroundcontrol,CornerOfSkyline/qgroundcontrol,kd0aij/qgroundcontrol,mihadyuk/qgroundcontrol,ethz-asl/qgc_asl,CornerOfSkyline/qgroundcontrol,RedoXyde/PX4_qGCS,kd0aij/qgroundcontrol,CornerOfSkyline/qgroundcontrol,ethz-asl/qgc_asl,Hunter522/qgroundcontrol,Hunter522/qgroundcontrol,ethz-asl/qgc_asl,kd0aij/qgroundcontrol,Hunter522/qgroundcontrol,mihadyuk/qgroundcontrol,mihadyuk/qgroundcontrol,ethz-asl/qgc_asl,kd0aij/qgroundcontrol,mihadyuk/qgroundcontrol,RedoXyde/PX4_qGCS,CornerOfSkyline/qgroundcontrol,ethz-asl/qgc_asl,Hunter522/qgroundcontrol,kd0aij/qgroundcontrol,CornerOfSkyline/qgroundcontrol,kd0aij/qgroundcontrol,Hunter522/qgroundcontrol,RedoXyde/PX4_qGCS,mihadyuk/qgroundcontrol,RedoXyde/PX4_qGCS,mihadyuk/qgroundcontrol,Hunter522/qgroundcontrol,RedoXyde/PX4_qGCS,RedoXyde/PX4_qGCS