Update/gitlab ci

.gitlab-ci/clang10-mpi-coverage.yml

-coverage:clang10-mpi-coverage:
-  image: localhost:5000/ubuntu_clang10_mpi
-  stage: coverage
-  script:
-    - mkdir -p build/clang10-cov-mpi
-    - cd build/clang10-cov-mpi
-    - CXX=clang++-10 CC=clang-10 cmake ../.. -DCMAKE_BUILD_TYPE=Coverage -DCLANG_FORMAT=/usr/bin/clang-format-10
-    - make pugs
-    - make coverage
-  cache:
-    key: "${CI_COMMIT_REF_SLUG}-clang10-cov-mpi"
-    paths:
-      - build/clang10-cov-mpi
-    untracked: true