Fixed obsolete call to PipetteMotor.release.
Fixed obsolete call to PipetteMotor.release.

"Why would I need to test this before pushing? Obviously release
doesn't do anything."

OpenTrons/opentrons_sdk,Opentrons/labware,OpenTrons/opentrons-api,OpenTrons/opentrons-api,OpenTrons/opentrons-api,OpenTrons/opentrons-api,OpenTrons/opentrons-api