'architecture' label not required for input to atomic-reactor

[twaugh]

Red Hat and Fedora container images are built using atomic-reactor, and while the 'architecture' label is required to be present in the built images, in fact it is added automatically by atomic-reactor.

In other words, the Dockerfile in the git repository serves as input to atomic-reactor, which adds a set of labels before building. 'architecture' is one of those labels.

I'd suggest removing the requirement to have 'architecture' present in the Dockerfile for Red Hat and Fedora container images.

[lachmanfrantisek]

The dockerfile checks are not ready yet, but you are right -- we should differentiate checks for the image/container and the Dockerfile. (Since we decided to check the automatically added labels as well.)

Thank you for pointing it out.