drgctl v0.4.0

This release is compatible with drogue-cloud 0.4.0.
Previous drg config files are not compatible with this version.

Changelog :

• Adding support for multiples contexts.
• Create resources from json files
• update resources from json files
• Changed config file to YAML.
• Pull default app and active context from env variables.
• automatically open browser when logging in
• --data renamed to --spec. See -f option to pass a full data object.

See blog post for usage details.