requirements: pin lxml==4.3.5 for py35 as well
not just py27.
https://travis-ci.org/fonttools/fonttools/jobs/564917367
Maybe the latest lxml is casting the attributes to a built-in dict type,
which only retains the insertion order from 3.6 onwards?
diff --git a/requirements.txt b/requirements.txt
index c2c8a48..5b63689 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,7 +9,7 @@
munkres==1.1.2; platform_python_implementation == "PyPy" and python_version >= '3.5'
zopfli==0.1.6
fs==2.4.8
-# lxml 4.4.0 breaks OrderedDict attributes in py27 so we pin to previous version
+# lxml 4.4.0 breaks OrderedDict attributes in python < 3.6 so we pin to previous version
# https://bugs.launchpad.net/lxml/+bug/1838252
-lxml==4.3.5; python_version < '3.5' # pyup: ignore
-lxml==4.4.0; python_version >= '3.5'
+lxml==4.3.5; python_version < '3.6' # pyup: ignore
+lxml==4.4.0; python_version >= '3.6'
