Init mayday, collecting legs and standing up

[LasseBoerresen]

• [x] init single dxl
• [ ] init legs, enable torque etc.
• [ ] create abstract class motor, dxl should inherit from motor
• [ ] warn about tucked underneath legs, femur actuator too low angle, tibia actuator too low angle
• [ ] collect a single leg
• [ ] collect each leg, one at a time
• [ ] stand up

[LasseBoerresen]

had to install pip install urdf_parser_py in order to get xacro model of mayday