How to test if a bipolar stepper motor is working?
The stepper motor you have needs a bridge driver, not a unipolar drive like a Darlington transistor. 

Also, the "move" loop needs 4 steps, changing the state of one winding at a time. Yours only has 3 steps; so at "goto move" you reverse both windings which will stall the motor.

The driver you  have can pull one end of a coil down to 0V. Which works fine if you can permanently wire the other end to 5V (or other V+) This is the way steppers with 4 separate coils are wired. 

But a bridge driver can pull to either 0V or 5V - and you can see that you have to do this - if red is 0V, green must be 5V, and vice versa. One example op a bridge driver is the L293D which is used on the AdaFruit motor shield among other places. "Figure 2" in that datasheet shows one way to use it (with inverters generating 2 of the 4 input bits, where you are using 4 port bits).

Four step switching sequence :
move:
10 10
01 10
01 01
10 01
goto move

Hopefully this is enough information to get you started.