PyYAML bug workaround

Change-Id: I75f9a7dbc9e5982b97f1dcecdcd28ed74f42f473
Signed-off-by: Mark Beierl <mark.beierl@canonical.com>
diff --git a/requirements.in b/requirements.in
index cc55f0d..abddaa5 100644
--- a/requirements.in
+++ b/requirements.in
@@ -34,6 +34,6 @@
 python-novaclient
 python-cinderclient==8.3.0
 pyvcloud
-pyyaml==5.4.1 # dependency comes from common
+pyyaml==5.3.1
 requests
 six