Linear actuator for byj48 stepper motor

Linear actuator
byj48 stepper motor.
ULN2003 stepper driver used
x2 M3 16mm
x2 M3 10mm

###Wiring
Arduino D6 ----- IN1
Arduino D7 ----- IN2
Arduino D8 ----- IN3
Arduino D8 ----- IN4

Arduino Code added 3/2/19:

3 args
moveInches(#ofInches to move, direction ("left" or "right"), speed [2-10])
moveMM(#of millimeters to move, direction ("left" or "right"), speed [2-10])