Kalunge/create new user account api endpoint

[Kalunge]

This pull request adds a user registration endpoint to the Sinatra application. The endpoint accepts a POST request with JSON data containing the user's email and password. Upon successful registration, a JSON Web Token (JWT) is generated for the user, which can be used to authenticate future requests. The UserController class has been created to handle the /register endpoint. The class includes error handling for missing email and password fields in the JSON data, allows cross-origin requests, and generates a JWT token for the user upon successful registration.

Changes Made

• Added a new UserController class to handle user registration.
• Added a new /register endpoint to the application for user registration.
• Defined a post request handler for the /register endpoint in the UserController class.
• Extracted the email and password fields from the JSON data passed in the request body.
• Included error handling to check if the email and password fields are present in the JSON data.
• Generated a JWT token for the user upon successful registration.
• Return the generated JWT token in the response in JSON format.

[github-actions]

Visit the preview URL for this PR (updated for commit 363973c):

https://moringa-library--pr48-kalunge-create-new-u-e30r6l4w.web.app

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[otsembo]

Hello @Kalunge, great initial PR.
There are some changes I have requested in the comments.

The database migration files will be ready by tomorrow so that you can use the validation errors that have been added. In the meantime, you can work on any of the comments that do not need the user db models right now.

[otsembo]

Since we are using Rack, we do not need the require statements at the top. Everything will be automatically set up by the bundler. Ensure the gems are listed in the Gemfile and everything should work accordingly.

[otsembo]

Instead of inheriting Sinatra::Base in every controller, inherit the Base Controller, it will have all the header options and formatting methods by default. You won't need to set them up afresh in every single controller.

[otsembo]

Kindly store your JWT_SECRET in an environment variable.
Secrets should not be exposed directly in code.

[otsembo]

Once you inherit the BaseController, all these methods are no longer needed. You can safely delete these methods.

[otsembo]

You can omit these checks since you will have been provided with validations on the model already. The validations will have customized error messages already.

[otsembo]

You can generate the JWT token after the user is successfully registered. You can move this code after you've created a valid user account.
Also, please make sure you add a timeout for the token. (You can have it set at 6 hours)

[otsembo]

Hello @Kalunge
You have API checks that are failing. Kindly fix those first.