CLI: Logout

[jonsharratt]

What did you implement:

Add logout cli support as per #71 @ganapativs

How did you implement it:

Takes the passed token then uses GitHub to reset it. One thing to note is that there is about a 4-5 sec cache before the custom authoriser then says it is invalid after testing.

How can we verify it:

• Get branch and deploy it
• Use npm logout
• Attempt npm publish

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Tag ready for review or wip

Is this a breaking change?: NO