Merge pull request #768 from Imberflur/safety

Merge pull request #767 from Imberflur/fixes-for-release

Merge pull request #753 from amethyst/release-numbers

prepare release `0.18.0` and switch to the recommended license format…

Release 0.17.0

Merge #686

686: Meta/685/release 0 16 1 r=azriel91 a=azriel91

Prep for #685.

Co-authored-by: Azriel Hoh <azriel91@gmail.com>

Merge #683

683: Maintenance/682/ongoing code maintenance r=azriel91 a=azriel91

Fixes #682,

## Checklist

* **n/a** I've added tests for all code changes and additions (where applicable)
* **n/a** I've added a demonstration of the new feature to one or more examples
* **n/a** I've updated the book to reflect my changes
* **n/a** Usage of new public items is shown in the API docs

## API changes

Updated `rayon` to `1.3.0`, and `uuid` to `0.8.1`.

Co-authored-by: Azriel Hoh <azriel91@gmail.com>

Merge #683

683: Maintenance/682/ongoing code maintenance r=azriel91 a=azriel91

Fixes #682,

## Checklist

* **n/a** I've added tests for all code changes and additions (where applicable)
* **n/a** I've added a demonstration of the new feature to one or more examples
* **n/a** I've updated the book to reflect my changes
* **n/a** Usage of new public items is shown in the API docs

## API changes

Updated `rayon` to `1.3.0`, and `uuid` to `0.8.1`.

Co-authored-by: Azriel Hoh <azriel91@gmail.com>

Merge #641

641: Bump version to 0.15.1 r=torkleyy a=torkleyy



Co-authored-by: Thomas Schaller <torkleyy@gmail.com>

Merge #606

606: Prepare for 0.15.0 release r=azriel91 a=torkleyy

## Checklist

* [x] I've added tests for all code changes and additions (where applicable)
* [x] I've added a demonstration of the new feature to one or more examples
* [x] I've updated the book to reflect my changes
* [x] Usage of new public items is shown in the API docs

## API changes

* Remove multiple methods from `WorldExt` which were moved to `shred::World` (see amethyst/shred#141)


Co-authored-by: Thomas Schaller <torkleyy@gmail.com>
Co-authored-by: Azriel Hoh <azriel91@gmail.com>

Update Changelog, bump versions