merged master

.gitlab-ci.yml

CMakeLists.txt

LICENSE

README.md

ci/docker_images/ubuntu/bionic/Dockerfile

ci/docker_images/ubuntu/bionic_cuda/Dockerfile

ci/scripts/config.sh

ci/scripts/test.sh

cmake/HysopVersion.cmake

docs/sphinx/users_guide/advection.rst

examples/analytic/analytic.py

examples/bubble/periodic_bubble.py

examples/bubble/periodic_bubble_levelset.py

examples/bubble/periodic_bubble_levelset_penalization.py

examples/bubble/periodic_jet_levelset.py

examples/example_utils.py

examples/particles_above_salt/particles_above_salt.py

...les/particles_above_salt/particles_above_salt_periodic.py

.../particles_above_salt/particles_above_salt_symmetrized.py

examples/scalar_advection/scalar_advection.py