Basic Authentication

[hannahhall]

As the Rare product owner, I would like all users to be authenticated in order to perform any activity in the system so that the system will be able to record which user created post, comment, etc... and EVENTUALLY restrict access to certain features based on user and user type permissions.

Given an unauthenticated user is in the Rare application
When they click any link
Then they should be prompted to login using their email address

Given an unauthenticated user is viewing the login form
When they enter an email address that matches an existing User Profile
Then they should be authenticated into the system
And they should be directed to the application home page

Given an unauthenticated user is viewing the login form
When they enter an email address that does not match an existing User Profile
Then an error message should be displayed
And the user should be given another change to enter a valid email address

NOTE: For the time being it is acceptable to treat all users as admin users. There is a future story about enforcing user permissions.