Added table of contents to epub.

tests/test_make_sheets.py

@@ -55,10 +55,10 @@ class MakeSheetsTestCase(unittest.TestCase):
 class EpubOutputTestCase(unittest.TestCase):
     gm_epub = Path(f"{GMFILE.stem}.epub").resolve()
 
-    # def tearDown(self):
-    #     for f in [self.gm_epub]:
-    #         if f.exists():
-    #             f.unlink()
+    def tearDown(self):
+        for f in [self.gm_epub]:
+            if f.exists():
+                f.unlink()
 
     def test_file_created(self):
         # Check that a file is created once the function is run