Remove test since function not being used

tests/unit/util/test_fs.py

-"""Unit tests for fs module"""
-from unittest.mock import patch
-
-from sbws.util import fs
-
-
-def mock_df_zero(path):
-    return 0
-
-
-def mock_df_enough(path):
-    return 89
-
-
-@patch('sbws.util.fs.df', mock_df_zero)
-def test_is_low_space_true(caplog, conf):
-    assert fs.is_low_space(conf) is True
-    assert ' is less than ' in caplog.records[-1].getMessage()
-
-
-@patch('sbws.util.fs.df', mock_df_enough)
-def test_is_low_space_false(conf):
-    assert fs.is_low_space(conf) is False