Add app to Joinfuse Site

This adds an app to the Joinfuse site. This is the initial version that allows Fuse users to manage their accounts, link to Carvoyant, and add vehicles. 

Still to do:

- Adding a vehicle doesn't add it in Carvoyant (this is an API issue)
- Deleting a vehicle doesn't delete it in Carvoyant (this is an API issue)