Add html coverage report

.gitlab-ci.yml

@@ -9,6 +9,7 @@ build_code:
     - bundle exec pod install 
     - bundle exec scan --scheme Api-Example --code_coverage --derived_data_path build
     - bundle exec slather coverage -s --scheme Api-Example --workspace Api.xcworkspace --build-directory build --binary-basename Api Api.xcodeproj
+    - bundle exec slather coverage --html --output-directory test_output/coverage --scheme Api-Example --workspace Api.xcworkspace --build-directory build --binary-basename Api Api.xcodeproj
   tags:
     - ios
   artifacts: