Interface with new stepper motor

[AbBaSaMo]

While we're waiting on the outcome for issue #39 we will create an interface for a new motor MSTI gave us so that if the old one doesn't work, we will just go ahead and use this one.

This task has the following requirements

• create a note that has a service get_position that is the EXACT same interface and types as the dynamixel one
• the service gets a position and the node interfaces with the servo and spins it to that position

[Jiawei-Liao]

Do you know what the servo brand/model is?

[AbBaSaMo]

@Jiawei-Liao not really. the brand and serial number is on the image someone on slack messaged under the software channel. You'll have to ask them or maybe @shrayb would know