Fix old geomedian nodata issue (#69)

- Fix crash when `hdmedians` GeoMedian statistics is run

NOTES:
- The crash reports that all the bands do not have the same `nodata` value
- This was caused by `nodata` being set to NaNs (and the fact that NaN != NaN)
- Output measurement type of GeoMedian should be the same as the input

datacube_stats/statistics.py

@@ -805,19 +805,6 @@ def compute(self, data):
 
             return data.transpose(*to).to_dataset(dim='variable')
 
-        def measurements(self, input_measurements):
-            """
-            Outputs will have the same name as inputs, but dtype will always be float32.
-            """
-            output_measurements = [
-                {attr: measurement[attr] for attr in ['name', 'dtype', 'nodata', 'units']}
-                for measurement in input_measurements]
-            for measurement in output_measurements:
-                measurement['dtype'] = 'float32'
-                measurement['nodata'] = np.nan
-
-            return output_measurements
-
         @staticmethod
         def _vars_to_transpose(data):
             """

datacube_stats/version.py

@@ -5,4 +5,4 @@
 dependencies imported in datacube_stats/__init__.py that are not present until after
 install. Do not import anything into this module."""
 
-__version__ = '0.9a7'
+__version__ = '0.9a8'