User Story: OAuth Github integration

As a member of Founders and Coders, who wants to learn from my fellow devs

> I want to log in with my Github account
So that I can use my Github organisation's info to see posts from my fellow students.

- [x] I can click on a button, which allows me to log in via my Github account
- [x] The look of the button should make it obvious that it is this form of login
- [x] Once I'm logged in, I should see a list of blog posts
- [x] I shouldn't be left with a blank loading screen for too long during the authorisation process, otherwise I will lose confidence in your website and leave.