Cleaning up busybox example

[jimi-c]

• Moves busybox/ -> roles/busybox/ and modifies the Dockerfile to properly copy the roles directory into the container image.
• Removing duplicate use of roles: busybox from playbook.yml since import_role is already running the required role.
• Added gather_facts: no as no facts appear to be used in the example (this will speed up execution of the playbook slightly).

Signed-off-by: James Cammarata jimi@sngx.net