account for ubuntu/mac float differences

pysyndna/tests/test_calc_cell_counts.py

@@ -657,7 +657,11 @@ def test_calc_ogu_cell_counts_biom_w_cast(self):
             params_df, self.linregresses_dict, counts_biom, lengths_df,
             read_len, min_coverage, min_rsquared, output_metric)
 
-        self.assert_biom_tables_equal(expected_out_biom, output_biom)
+        # NB: only checking results to 2 decimals because Ubuntu and Mac
+        # differ past that point. Not that it matters much since the decimal
+        # portion of values this huge is not very important.
+        self.assert_biom_tables_equal(expected_out_biom, output_biom,
+                                      decimal_precision=2)
         self.assertListEqual(
             ["The following items have coverage lower than the minimum of 1: "
              "['example2;Neisseria subflava', "