Create a basic Rails app

1. Create a new Rails app; name it however you want
2. Create a Post model with content attributes; think of "posts" as Facebook posts
3. Create a User model with username, email, first_name and last_name attributes
4. A user has many posts; create this relationship
5. Create the following endpoints:
   • CREATE /users: create new user
   • CREATE /posts: create new posts; accept user_id to relate a post to a user
   • GET /posts: list all posts
   • PUT /posts/:id: modify a post identified by the post's ID
6. Bonus
   • DELETE /posts/:id: delete a post