allow submitting by providing repo + commit

[lukasheinrich]

One thing that would be awesome is to have a binder-like interface that allows you to
submit without having to clone

reana-client submit --fromrepo https://github.com/reanahub/reana-demo-atlas-recast.git@master 

and a similar interface on the reana web ui

[tiborsimko]

(A somewhat related issue is to pass the git status information from local repository, so that each workflow run would have git commit repository and status information displayed in the UI, as is the case for workflow runs triggered from GitLab.)

[lukasheinrich]

could also become a nice badge "Run on REANA"

[tiborsimko]

Yes, such a badge was in the horizon!