made get_measurement_parameters() an api function

sensospot_data/parameters.py

@@ -48,7 +48,7 @@ def _parse_measurement_params(params_file):
     return result
 
 
-def _get_measurement_params(folder):
+def get_measurement_params(folder):
     """ returns measurement parameters """
     params_file = _search_measurement_params_file(folder)
     if params_file is not None:
@@ -72,7 +72,7 @@ def add_optional_measurement_parameters(data_frame, folder):
     """ adds measurement params to the data frame, if they could be parsed """
     data_frame[COL_NAME_PARAMETERS_CHANNEL] = numpy.nan
     data_frame[COL_NAME_PARAMETERS_TIME] = numpy.nan
-    params = _get_measurement_params(folder)
+    params = get_measurement_params(folder)
     if params:
         available_exposures = set(data_frame[COL_NAME_EXPOSURE_ID].unique())
         if available_exposures == set(params.keys()):