Change: Update phoenix to v0.18.0

Tags: web

We updated phoenix to v0.18.0. Please refer to the changelog (linked) for details on the phoenix release. With the ODS release brought in by phoenix we now have proper oc-checkbox and oc-radio components for the settings and accounts UI.

https://github.com/owncloud/ocis/pull/651
https://github.com/owncloud/phoenix/releases/tag/v0.18.0
https://github.com/owncloud/owncloud-design-system/releases/tag/v1.12.1
