2.10 2019-01-02

* The "periodic" subcommand

The new subcommand "periodic" is responsible for maintaining the job database.
It finishes up pending glacier jobs, dowloading the results (both inventory
listings and requested files) and removes expired jobs. It should be run as a
cronjob.

* When run on an EC2 instance, credentials can be obtained from the EC2 metadata

* Directory validity is controlled using the LastInventoryDate field

2.00 2018-03-08

* Redo the class system.

1.00 2018-02-24

* Initial release.