Update authentication initializer.

Refs #3492
- ember-simple-auth@0.7.2
About Page Tests

Closes #4508

Tests for:

- Version number is a number
- Database type is an allowed 1 of 3
- There are 20 contributors
- First contributor has an image tag and image src exists, alt tag, title tag, href to github
Move testem.json into client tests directory.
Merge pull request #4570 from jaswilli/update-simple-auth

Update authentication initializer.
Merge pull request #4587 from jaswilli/testem

Move testem.json into client tests directory.
Merge pull request #4579 from PaulAdamDavis/about-tests

About Page Tests
Update syntax in ember templates.

No Issue.
- Outlet names must be quoted.
- {{#each}} helper will no longer implicitly switch context.
  Change usage to {{#each foo in bar}}.
Merge pull request #4594 from jaswilli/ember19-prep

Update syntax in ember templates.
Merge branch 'master' of https://github.com/TryGhost/Ghost

Conflicts:
	core/client/templates/components/gh-role-selector.hbs
	core/client/templates/posts.hbs
	core/client/templates/settings/about.hbs
	core/client/templates/settings/users/index.hbs