metrics: Add script to measure time for docker workloads
metrics: Add script to measure time for docker workloads

Add a moderately generic script that measure time taken for
the requested docker workloads.
A common use case is to time the create/run/delete round trip
time of '/bin/true', but the script can also be used for other
commands.

Signed-off-by: Graham Whaley <95f36e5ac6982f4574a5c449c37cf652e934d2b9@intel.com>

bwarden/tests,GabyCT/tests,clearcontainers/tests,bwarden/tests,chavafg/tests,sboeuf/tests,clearcontainers/tests,devimc/tests,MarioCarrilloA/tests,sboeuf/tests,chavafg/tests,GabyCT/tests,MarioCarrilloA/tests,devimc/tests