Update test_lineardensity.py

Author: BFedder

testsuite/MDAnalysisTests/analysis/test_lineardensity.py

@@ -51,7 +51,7 @@ def test_grouping_atoms():
     assert_almost_equal(ld.charges, expected_charges)
     assert_almost_equal(ld.results['x']['pos'], xpos)
 
-    
+
 def test_grouping_residues():
     """For testing the case of grouping='residues'"""
     universe = mda.Universe(waterPSF, waterDCD)
@@ -78,7 +78,7 @@ def test_grouping_segments():
     assert_almost_equal(ld.masses, expected_masses)
     assert_almost_equal(ld.charges, expected_charges)
 
-    
+
 def test_grouping_fragments():
     """For testing the case of grouping='fragments'"""
     universe = mda.Universe(waterPSF, waterDCD)