run-unit-test-docker.sh: clean up copied scripts

The tool copies some scripts to the workspace directory. It appears this
is done so that the permissions can be changed, as opposed to
potentially changing the repo containing the scripts.

Updated the tool to removed this copied scripts after the tool finishes
successfully.

Change-Id: I8b1be3b05d007da7e1f55df776d0dffcbc712d77
Signed-off-by: Zane Shelley <zshelle@us.ibm.com>
1 file changed