send-counter: fix & test

This fixes the bin/ceilometer-send-counter program that has been broken
after the implementation of multi-publisher.
We also add a test to see if it runs!

This fixes bug #1133226

Change-Id: I922c7a000e942ee28d840f4cd65d13898d6d23a8
Signed-off-by: Julien Danjou <julien@danjou.info>
Merge "send-counter: fix & test"