Fixed Python coverage

.gitlab/ci/coverage.gitlab-ci.yml

@@ -28,7 +28,9 @@ coverage:ubuntu_python:
     - source venv/bin/activate
     - python3 -m pip install numpy coverage
     - cd ${CI_PROJECT_NAME}
-    - python3 -m coverage run --source=. -m unittest discover -s unit_tests/ -v -b
+    # Retrieve the installation path of the module, since it is installed with pip.
+    - export MODULE_LOCATION=`python -c "import ${CI_PROJECT_NAME} as _; print(_.__path__[0])"`
+    - python3 -m coverage run --source=$MODULE_LOCATION -m unittest discover -s unit_tests/ -v -b
     - python3 -m coverage report
     - python3 -m coverage xml
   coverage: '/(?i)total.*? (100(?:\.0+)?\%|[1-9]?\d(?:\.\d+)?\%)$/'