provide a cmd to pull the image in WebUI

[vpavlin]

User should be able to easily find an URL to pull the image

Something like

Pull:

• dbs-stg2.usersys.redhat.com:5000/testuser/rebuild_virsh:latest

would be ok

[TomasTomecek]

Client already has this information:

https://github.com/DBuildService/dbs-server/blob/master/dbs/api/core.py#L146

therefore this should be trivial to implement

[vpavlin]

Great, just be careful with hardcoding the port: 'dock pull %s:5000/%s'" - there is no certainty registry has to run on port 5000 (I know this is just the PoC version, #justsaying:)

[TomasTomecek]

Good point. We should add internal registry address to configuration.