* we need to use reference ( docker API it doesn't support tag name )
* fix tag date (value in the first occurrence not last)
Change-Id: I2fa2f7bedaca4cdeeb3a3a2d4a3f4a661d15fad1
* provide info of actual images and tags
* refresh docker images/tag via release_dashboard
* keep that info in db
* fix Dockerfile documentation
* cleanup thanks to flake8
Change-Id: I743482da9b4d50f7b1832cad324882f3a49cbcf0