Installs Thesis by adding these to your host app:

• lib/thesis_auth.ex - Contains a function to handle authorization
• migration - creates the two tables needed for Thesis.EctoStore
• config/config.exs - adds Thesis config code
• web/web.ex - adds Thesis use statements

You should be able to run this mix task multiple times without harm. It will automatically detect when a file or line of code exists and skip that step.