v0.8.0

• Added a new profile login option: login with a web browser (#50)

Now you can authenticate spacectl without providing any tokens or static credentials:

> spacectl profile login my-account
Enter Spacelift endpoint (eg. https://unicorn.app.spacelift.io/): http://my-account.app.spacelift.tf
Select authentication flow: 
  1) for API key,
  2) for GitHub access token,
  3) for login with a web browser
Option: 3