Pyuploadcare

- Fixed issue with missing `ucare_cli` package.

- Added support for version 0.5 of REST API.
- Updated widget to version 2.8.1 (see [widget changelog](https://github.com/uploadcare/uploadcare-widget/blob/master/HISTORY.markdown)).
- Added the `ucare list_groups` command.
- Removed deprecated entities.

**NB**: There are backward incompatible changes. For detailed
information about the upgrade process see [update to version 2.0](https://pyuploadcare.readthedocs.io/en/stable/install.html#update-to-version-2-0).

- Fixed ZeroDivision error when trying to sync files with no size

- Added support of Django 1.9
- Removed indication of Unicode strings from output of `ucare`
- Fixed a group representation for `ucare create_group` command
- Fixed error with `ucare sync` when trying to processing of not image files

- Added storage operations
- Added request\_limit to ucare\_cli

- Expanded User-Agent