This improves the TestBuildSixtySteps test by switching from busybox to scratch and simply adding a file. This lowers the execution time of that test from 20 seconds to 5 seconds. Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack) Upstream-commit: 58c11ee0a8be74562b0e6f88ee000afdf9ddf025 Component: engine