Resolve "Add filtering to push notifications"

Luko van der Maas
2018-03-14T14:31:41+01:00

~feature Closes #538 ### Short description - Gave the device an option to choose which categories will be send to that device. - Added a category field to the message. - Added an API to change device settings for categories and listing them. ### Steps to use this feature 1. Get the list of categories from the API: `/api/v1/device/categories` 2. Change the categories alowed of a device via the API: `/api/v1/device/` 3. Add a message via the admin and set the category 4. Click on send. Now only the device that have the category of the message set should get the message.