travis: Use python-tornado<5.0.0 to workaround build issue

paluh · paluh · commit 3a71e6c7bc37 · 2018-05-31T19:56:18.000+02:00
diff --git a/docs/requirements.txt b/docs/requirements.txt
@@ -1,3 +1,4 @@
+tornado<5.0.0
 sphinx
 semver
 sphinx-autobuild

-Original file line number
+Diff line change
@@ @@ -1,3 +1,4 @@ @@
 +tornado<5.0.0
 sphinx
 semver
 sphinx-autobuild