Merge branch 'fix/2.0/perf' of https://gitlab.inria.fr/solverstack/ScalFMM into fix/2.0/perf

.gitlab-ci.yml

-image: hpclib/hiepacs
+image: registry.gitlab.inria.fr/solverstack/docker/distrib
 
 before_script:
   - source /usr/share/modules/init/bash && source /usr/local/share/spack/setup-env.sh && spack load cmake@3.14.4