Merge branch 'release/1.6.0'
_ask_for_credentials: default_email is put in prompt *only* if it is string. CLI passes a non-string args (a Namespace).
Merge branch 'hotfix/cli-login'

Address issue #47 - weird name on cli login
Bump version: 1.6.0 → 1.6.1
Merge branch 'hotfix/bump' into dev