Use clair-whitelist.yml, not clair-whitelist.yaml

This MR fixes 2 things:

1. Use clair-whitelist.yml instead of clair-whitelist.yaml. The docs are correct and refer to clair-whitelist.yml which will support backwards compatibility with existing whitelists, however, the whitelist handling code added by !4 (merged) was using clair-whitelist.yaml by mistake
2. Remove the version from the docker image name for use in the whitelist. This is done to implement the same behaviour as clair-scanner