Add login page
Login#new => Session#new
Create authorizations table

[ci skip]
Create users table

[ci skip]
Add user id foreign key to authorizations table

[ci skip]
Gemfile tweaks
Update database schema file
Fix spec filename
Update database schema file
Set environment variables for all environments
Block external API requests
Staff members can authenticate using their github accounts
Merge pull request #13 from webdevtalks/auth

Staff members can authenticate using their github accounts