cli: reana-dev git-upgrade fails silently

[diegodelemos]

When running git-upgrades sometimes it happens that a component update fails and then the next ones are not called.

$ reana-dev git-upgrade
[pytest-reana] git fetch upstream
[pytest-reana] git checkout master
Already on 'master'
[pytest-reana] git merge --ff-only upstream/master
Already up to date.
[pytest-reana] git push origin master
Everything up-to-date
[pytest-reana] git checkout -
Already on 'master'
[reana-workflow-engine-yadage] git fetch upstream
[reana-workflow-engine-yadage] git checkout master
Already on 'master'
Your branch is up to date with 'origin/master'.
[reana-workflow-engine-yadage] git merge --ff-only upstream/master
Already up to date.
[reana-workflow-engine-yadage] git push origin master
Everything up-to-date
[reana-workflow-engine-yadage] git checkout -
Already on 'master'
Your branch is up to date with 'origin/master'.

So, in this case, it would fail after upgrading R-W-E-Yadage so next components in the queue won't be upgraded.