Update pillow dependency in setup.py

setup.py

@@ -73,7 +73,7 @@ install_requires = [
     "MarkupSafe>=1.0",
     "mistune>=0.8.3",
     "olefile>=0.45.1",
-    "Pillow>=5.1.0",
+    "Pillow>=7.1.2",
     "pluggy>=0.6.0",
     "Pygments>=2.2.0",
     "python-dateutil>=2.7.3",