Hybrid Rocket Equations of Motion

[MateusStano]

Short Description:
Important modification on the Flight Class

Long Description:
Document (and maybe implement) equations of motion for hybrid motors. Currently equations of motions relies on the hypothesis of constant position of the center of mass of propellant, which is not true for hybrid or liquid motors

Useful links:
https://drive.google.com/file/d/1HFDmLuQ65gRiR_I-2Ocy67TkZbSvGeOF/view?usp=sharing