Add coverage check to gitlab ci

Author: csc-jm

.coveragerc

@@ -7,6 +7,8 @@ omit =
     /usr/*
     # omit this single file
     swift_browser_ui/__init__.py
+    # omit test files
+    tests/*
 
 [report]
 # Regexes for lines to exclude from consideration

.gitlab-ci.yml

@@ -49,6 +49,9 @@ backend-test:
   script:
     - pnpm --prefix swift_browser_ui_frontend docker-build
     - tox -e pytest
+    - coverage run -m pytest tests/
+    - coverage report --precision=1
+  coverage: '/TOTAL.*\s+(\d+\%)/'
 
 build-ci-image:
   stage: build