Fix test for python style.

workflow/tests/test_call_peaks_macs.py

 #!/usr/bin/env python3
 
 import pytest
-import pandas as pd
-from io import StringIO
 import os
 import utils
-import call_peaks_macs
 
 test_output_path = os.path.dirname(os.path.abspath(__file__)) + \
                 '/../output/callPeaksMACS/'

workflow/tests/test_overlap_peaks.py

@@ -4,6 +4,7 @@ import pytest
 import pandas as pd
 from io import StringIO
 import os
+import utils
 import overlap_peaks
 
 test_output_path = os.path.dirname(os.path.abspath(__file__)) + \
@@ -26,7 +27,7 @@ def design_diff():
 
 def test_check_update_design(design_diff):
     new_design = overlap_peaks.update_design(design_diff)
-    assert df.shape[0] == 2
+    assert new_design.shape[0] == 2
     assert new_design.loc[0, 'control_bam_reads'] == "B_1.bam"
     assert new_design.loc[0, 'peak_caller'] == "bed"