Fix formatting

Author: ElliottKasoar

tests/test_abstract_model.py

@@ -1,15 +1,14 @@
 import io
+from io import StringIO
 
 import ase
-import pytest
-from pytest import approx
-
-from io import StringIO
+from ase.calculators.lj import LennardJones
 from ase.io import read, write
 import numpy as np
+import pytest
+from pytest import approx
 
 from abcd.model import AbstractModel
-from ase.calculators.lj import LennardJones
 
 
 @pytest.fixture