Add shell.py so we can do v2 shell commands

ceilometer --ceilometer-api-version 2  sample-list -m <meter>

fixes bug #1132633
Signed-off-by: Angus Salkeld <asalkeld@redhat.com>

Change-Id: I177c2f759b9b07b44dcd6dd20f457cefd036d0b9
Merge "Add shell.py so we can do v2 shell commands"