Enable users to publish to their Write.as account, making either anonymous posts or blog (collection) posts.
This is the primary functionality needed for writeas-cli v2.0.
This brings the CLI up-to-date with the basic functionality of the web application.
At a high level, the user should be able to authenticate with the CLI. Doing so should save their user information and access_token. Once authenticated, all API requests should be made with that access_token sent along. This ensures anonymous posts are created on the user's account, and the user can make posts to blogs on their account.
See sub-tasks for specific functionality.