Create login page

[niall-rb]

Description
After the app has loaded the user should be presented with a login page. They will be prompted to login with google and if successful be taken to the Interests setup page.

Out of scope

• User feedback if they don't complete the google sign in workflow
• Login expiration or similar

Acceptance criteria
GIVEN I am signing up for the first time
WHEN I log in using my google account
THEN I see a spinner while authenticating
AND I am redirected to the "Interests setup" page

GIVEN I have logged in before
WHEN I log in using my google account
THEN I see a spinner while authenticating
AND I am redirected to the "Home" page

Non-functional requirements
The design should match those provided in Badger Me App

Linked issues
Login & Signup Page
Google Auth Layer