Taiga-contrib-slack

- Fix a bug if the object owner has not a photo.

- Compatible with Taiga 2.1.0

- Compatible with Taiga 2.0.0
- Now we use gulp to improve the dev process.

- Compatible with Taiga 1.10.0

- [Front] Migrate to the new plugin system
- Remove django dependency to prevent errors.

- Force to use Django == 1.8.5
- Add compatibility with taiga-back 1.9.
- [Issue 2926] Fix problem with escaping characters on creation.
- [Issue 2932] Show username and user photo in slack messages.
- Fixed problem with test button.
- Allow to configure what to notify.