bootstrap OSU Microbenchs tutorial

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
update README

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
add Git submodule on ULHPC launcher-scripts

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
add sample data

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
add sample Gnuplot script and sample data

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
add sample PNG

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>