docs: update to reana-client v0.3.0 cli
Created by: dinosk
Closes https://github.com/reanahub/reana-demo-helloworld/issues/28
Signed-off-by: Dinos Kousidis dinos.kousidis@cern.ch
Created by: dinosk
Closes https://github.com/reanahub/reana-demo-helloworld/issues/28
Signed-off-by: Dinos Kousidis dinos.kousidis@cern.ch