Release 2.1.0.rc.1

Highlights:

• Enabled support for swift object storage as a backend to store optimized images.

Upgrade:

• See the migration guide for details.

Changelog:

• Updated GDAL to version 2.3
• Added additional configuration parameters to enable and tune the swift storage
• Added middleware to handle authorization keys
• Added command to rewrite file references to point to object storage
• Implemented upload to object storage during ingest when it is enabled