Changes since last version
--------------------------
* c7cb189: Ignore .pip_cache, so semaphore builds can be published
* 15314db: Rewrite code to accommodate PEP-479 related to use of StopIteration
* 8ae6fd9: Fix copy-paste error
* 9e03766: Clean up leftovers
* ee3777b: Basically copied the semaphore setup from fiaas/publish
* 8ac01bc: Make it possible to use other label selectors than equality
* bf2743f: Drop support for Python 3.4 and bump dependencies.
* 8c3bb8a: Set a timeout for watch connections
* fb82324: Add support for watching Ingress and Service
* 145ebfb: Bump versions
* f88b460: Set a returncode to reflect errors when uploading artifacts