drgctl v0.3.0

This release is compatible with drogue-cloud 0.4.0.

Changelog :

• Added openId support as authentication is now required for drogue cloud.
• Config file contains authentication token and connection details to drogue cloud. See login sub command.
• Json outputs are colored and prettier.
• If something wrong happens drg will return non 0 return values.
• version sub commands now displays drogue cloud version when a valid configuration exist.
• published to crates.io
• verbose option
• --app option have a shorthand : -a