Fix coverage reporting

{{cookiecutter.project_slug}}/.gitlab-ci.yml

@@ -76,6 +76,7 @@ test:
     - mkdir coverage
     - gcovr -r .. -e ../test/ -e ../src/main.cpp --txt --xml coverage.xml --html-details coverage/coverage.html
     - tar cfz coverage.tar.gz coverage/
+  coverage: '/TOTAL.*?\ ([0-9\.]{1,}\%).*$/'
   artifacts:
     paths:
       # This will give a warning which is ok