Allow pipeline to be run manually

bitbucket-pipelines.yml

@@ -0,0 +1,9 @@
+image: python:3.7.3
+
+pipelines:
+  custom:
+    - step:
+        caches:
+          - pip
+        script:
+          - python pipeline.py

pipeline.py

@@ -0,0 +1,2 @@
+if __name__ == "__main__":
+    exit(1)  # Fail the pipeline