RK3 time stepping branch formerly source:/NEMO/branches/2021/dev_r14318_RK3_stage1 updated on git with main. SETTE partly tested : problem with AGRIF_DEMO.

Add a .gitlab-ci.yml to set up the ci of NEMO (need to be tuned once...

See merge request nemo/nemo!5

Add a .gitlab-ci.yml to set up the ci of NEMO (need to be tuned once discussion on host machine for runner finalised)

Resolve "xios not working when no ocean proc corresponds to xios proc"

Closes #1

See merge request nemo/nemo!3

Tried to restore correct time order to test directories by prepending date to short hash. Date is a 5-digit number constructed from a 2-digit year and 3-digit year-day