Redirect the app index to the users index

Also, as a learning exercise, link to the users index from the app index
template.
Link to user from users index

Create the template, the controller and the route for a user.
Create route and template for editing a user
Create action for transitioning to editing a user
Support saving and updating a user
Allow users to be deleted

Display a confirmation modal when the delete button is pressed, allow the user
to confirm or deny their deletion.
Allow users to be created

Utilize the edit form for creating users.
Add moment.js as a dependency
Create the helper for showing relative time

Use moment.js and a helper to make it happen. Note: with ember-cli, helpers must
be dash-erized in order for it to work in templates.
Change the creationDate for a user fixture

Make it closer to current time to see that relative dates are working.