Reportstate 11

Provisionally fixes #11
Opening PR with the expectation that there is probably a bit more stuff to do, but some comments would be appreciated.
It allows `flocker_reportstate_main()` to pass `FlockerScriptRunner` a `ReportStateScript` class instead of an object, which in turn allows `FlockerScriptRunner` to instantiate `ReportStateScript` with the parsed CLI options, which in turn allows `ReportStateScript.__init__` to call its `create_volume_service` callable with a configured path.