support for hpc2020 and house keeping

See merge request !10

Test run on MN4; remove redundant batch scripts and consolidate similar Slurm configurations for MN4 and HPC2020.

Merge branch 'devel-data-coupler-hpc2020' of https://earth.bsc.es/gitlab/es/python-amip-reader into devel-data-coupler-hpc2020

adding CO2FLUX support to DataCoupler

See merge request !9

[data-coupler-co2box] change transformation in namcouple generator when source...

See merge request !8

add support for co2box data coupler (no AMIP) using the new yaml interface

See merge request !6

# Conflicts:
#   tests/data/convert-ece4pyreader-grids.sh
#   tests/data/template_conf_datacoupler_forcing.yaml
#   tests/launch_ece3_data_coupler_mn4.cmd

[data-coupler-co2box] change transformation in namcouple generator when source and target grids are the same (e.g. GLOBAL for the co2box model)

Both DataCoupler and toyy_model are using the ece3/toy_model.py with a YAML input files. In addition, namcouple file for DataCoupller is generated automatically based on the YAML input. The CO2 E/C-modes are removed.

See merge request !4

Fixing all the issues that were raised in mr4. Also, preparing for future development: co2box & co2flux.

Resolved issue: Eliminating hard-coded MPI process type for partitioning, ensuring non-empty out_coupling_vars, and and no dependency on  MPI num_processes.