Moves the application of the conversion to the read_obspy module; this was in the StationTrace init method and was the reason for the bug since it is called both when the data is read in and then also when the data is retrieved from the HDF file.
Added a unit test for CSN SAC data; confirmed that the resulting values give similar results to a nearby permanent station.
Closes #992
read_obspymodule; this was in theStationTraceinit method and was the reason for the bug since it is called both when the data is read in and then also when the data is retrieved from the HDF file.