v3.1

Features:

This PR adds one field at the product and other at customers.

Also, when the user enters an order, the software gets the product price and the base discount for the selected product/client.

Related to #5;

v3.0

Features:

Maintain and register orders (create, read, update and delete)

Related to #4;

v2.0

Features:

Maintain and register customers (create, read, update and delete)

Related to #3;

v1.0

Features:

Maintain and register products (create, read, update and delete)

Related to #2;