Motor isn't spinned

[mike-shock]

I tried to run a 'quick & dirty script to spin a motor' from the 'Usage' description from page https://github.com/tehviking/brick_pi_ruby/.
Motor is not spinned from my Ruby program. But it is spinned forward and backward from the sample Python script.
What can be done to debug and test my program? Is there new version of the gem?

Environment: Ruby 2, 'brick-pi' gem v.0.4.0, Dexter Raspbian for Robots (2016.06.26 jessie), Raspbery Pi 3 model B (powered by 5V via micro USB) with BrickPi+ module (powered by 9V battery).