CWG-57: Add coverage in pipeline and badges to readmes

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

@@ -50,6 +50,7 @@ run_unit_tests_coverage:
   image: python:3.7
   script:
    - tox -e coverage
+  coverage: '/(?i)total.*? (100(?:\.0+)?\%|[1-9]?\d(?:\.\d+)?\%)$/'
   artifacts:
     reports:
       coverage_report: