Add getter for rad_per_count.
Remove unneeded line.
Add get_current and get_torque methods.
Rear motor controller implementation finalized.
Add a few constants and change a few to constexpr.
Rename SystemCommands to system_commands and clean up.
Made MPU6050 a normal non Singleton and clean up.
WIP: Converting sample and control code to new class heirarchy.
WIP: converting main.cpp to use new class heirarchy.
Add derivative_filter design script.