Resolve "Flake8 found issues after merge to master"

Closes #16 (closed)

test.py

@@ -77,10 +77,12 @@ def test_flux_splitting_uniform_grid(
             characteristic_fluxes_pos=fluxes_pos_dev,
             characteristic_fluxes_neg=fluxes_neg_dev)
 
-    fluxes_pos_expected = u.expand_to_6(u.transposed_array_from_string(fluxes_pos_expected_str))
+    fluxes_pos_expected = u.expand_to_6(
+        u.transposed_array_from_string(fluxes_pos_expected_str))
     u.compare_arrays(fluxes_pos_dev.get(), fluxes_pos_expected)
 
-    fluxes_neg_expected = u.expand_to_6(u.transposed_array_from_string(fluxes_neg_expected_str))
+    fluxes_neg_expected = u.expand_to_6(
+        u.transposed_array_from_string(fluxes_neg_expected_str))
     u.compare_arrays(fluxes_neg_dev.get(), fluxes_neg_expected)