The plural of 'datum' is 'data'

Please remove reference to 'datums'-- these are actually items used in geological surveys (per google: Datums are the basis for all geodetic survey work. Near coastal areas, mean sea level (and other tidal datums) is determined by analyzing observations from a tide gauge. This image shows a tide gauge at the St. Charles Parish Water Level Monitoring System in Louisiana.)

I'm getting logging information that looks like:

```
INFO: Successfully published 18 datums.
```

and that's just wrong, since I'm assuming the library isn't logging tide gauges.