Allow tags to be null

Fix: Allow tags to be null

Fixed double hydration

• Fixes issue with double hydration of ranking

Resource structure

• BC: Resource structure
• Creation of domains

Thanks to @jasonkellydk

Added the option to delete

Merge pull request #4 from jasonkellydk/master

PSR-2

Version 0.0.1

Merge pull request #1 from jasonkellydk/create-keyword

BC. Feat. Added support for creating keywords