Upgrade fonttools to 4.20.0

Test: make
Change-Id: I1dc195eaa683bce2c70b1c79ecb15abb20ea09ef
diff --git a/setup.py b/setup.py
index 7f13122..e3e7b52 100755
--- a/setup.py
+++ b/setup.py
@@ -441,7 +441,7 @@
 
 setup_params = dict(
 	name="fonttools",
-	version="4.19.1",
+	version="4.20.0",
 	description="Tools to manipulate font files",
 	author="Just van Rossum",
 	author_email="just@letterror.com",