update requirements

Author: b3b

buildozer.spec

@@ -46,7 +46,8 @@ requirements =
              able_recipe,
              https://github.com/b3b/midistream/archive/master.zip,
              mididriver,
-             Pillow,
+             Pillow==8.0.1,
+             docutils==0.16,
              requests==2.24.0,
              urllib3==1.25.9,
              certifi==2019.6.16,