send graphite markers upon starting test

[mmgaggle]

send a metric with a value of 1 to a specified graphite host with a key that matches the name of the test being run (matching the directory output structure)

0000000_radosbench_etc

Probably pretty easy with something like this:

https://github.com/daniellawrence/graphitesend

[mmgaggle]

The idea here would be to disable collectl, and rely on Calamari for collecting metrics during test runs. We could then use graphite's graph composer to quickly analyze the results of tests.