src/gc_content/gc_content.py: fix error to tests

src/gc_content/gc_content.py

@@ -77,7 +77,7 @@ def get_many_gc_content(bed_line: List[Any], dic_seq: Fasta,
     {'interval': 50.0}
     >>> get_many_gc_content(["chr1", 10, 20, "s1", ".", "+"],
     ... dic_seq, 10)
-    {'before': 10.0, 'interval': 50.0, 'after': 0.0}
+    {'before': 100.0, 'interval': 50.0, 'after': 0.0}
     >>> get_many_gc_content(["chr1", 10, 20, "s1", ".", "-"],
     ... dic_seq, 10)
     {'before': 0.0, 'interval': 50.0, 'after': 100.0}