Wagtail-simple-gallery

Updated to work with Wagtail 2.7 and django 2.2, might not work with earlier versions.

If upgrading:
- Remove the wagtail_simple_gallery from urls and use `WAGTAILIMAGES_INDEX_PAGE_SIZE = 32` setting instead.

v.0.6.4
Added a simple tag feature (12), thanks MorezMartin! Tested with wagtail version to 2.5.1 (Works).

Small fixes (10) and bumped wagtail version to 2.4.x.

Solved issue 9

Bumped support for Wagtail 2.2.x

**NOTE:** Removed support from Django and Wagtail versions below 2.0.

- Added support for Django 2.0.x and Wagtail 2.0.x. Thank you hongquan 😃
- Added a new setting value `SIMPLE_GALLERY_ADMIN_URL_ROOT`
- Fixed a bug with the `simple_gallery` inclusion tag that appeared on version 0.5.0.

- Added SIMPLE_GALLERY_TEMPLATE setting.