.gitlab-ci.yml: Add fallback tests to CI

.gitlab-ci.yml

@@ -26,7 +26,17 @@ tests:
 
 # Run integration tests
 #
-integration_tests:
+default_platform_tests:
+  script:
+    - dnf install -y findutils bzr
+    - pip3 install .
+    - git clone https://gitlab.com/BuildStream/buildstream-tests.git
+    - cd buildstream-tests
+    - ./run-test.sh --arg --colors test
+
+fallback_platform_tests:
+  variables:
+    BST_FORCE_BACKEND: "fallback"
   script:
     - dnf install -y findutils bzr
     - pip3 install .