Limiting number of parallel make jobs
Limiting number of parallel make jobs

Setting '-j 4' instead of '-j' on make step - observing gcc internal errors in travis build, which are
reproducible in a Docker container with unlimited parallel build jobs. Suspect source layout changes
increases number of possible parallel jobs, which causes issues in resource limited container.

percival-detector/odin-data,odin-detector/odin-data,odin-detector/odin-data,odin-detector/odin-data,odin-detector/odin-data,odin-detector/odin-data,percival-detector/odin-data,odin-detector/odin-data,percival-detector/odin-data,percival-detector/odin-data,odin-detector/odin-data,percival-detector/odin-data,percival-detector/odin-data,percival-detector/odin-data