Fixed flake8 warnings

W191 indentation contains tabs
W292 no newline at end of file
W293 blank line contains whitespace
W391 blank line at end of file

testing/python/approx.py

@@ -309,4 +309,3 @@ class TestApprox(object):
             '*At index 0 diff: 3 != 4 * {0}'.format(expected),
             '=* 1 failed in *=',
         ])
-

testing/python/fixture.py

@@ -3026,6 +3026,3 @@ class TestParameterizedSubRequest(object):
             E*{1}:5
             *1 failed*
             """.format(fixfile.strpath, testfile.basename))
-
-
-