Create interface for weight sensor

[patrickanguyen]

Description

Create an interface class for the distance sensor called IWeight. We are creating an interface, so we can create two classes for our mock distance sensor MockWeight class, and our real hardware sensor LoadCellWeight class. We are having the mock sensor so we can easily create unit tests without relying on real hardware.

Requirements

• Create a folder inside lib called Weight(All of the fullness related classes will go here) with the file IWeight.hpp
• Create a class called IWeight
• The class should have a pure virtual function called getWeight() that returns a int32_t (you might need to #include <cstdint>)