Draw schedule lines using a single spline

Closes #235 (closed)

.gitlab-ci.yml

@@ -29,6 +29,8 @@ before_script:
     # - lcov --list coverage.info
     # - find . -name '*.gc*' -delete
   artifacts:
+    paths:
+      - result_images
     reports:
       coverage_report:
         coverage_format: cobertura