Upgrading PyYaml due to new juju package

Change-Id: Idce6235e9bdd033d16d207734c9e1ddd0ed0453b
Signed-off-by: lavado <glavado@whitestack.com>
diff --git a/setup.py b/setup.py
index 032ee87..1cee33f 100644
--- a/setup.py
+++ b/setup.py
@@ -56,7 +56,7 @@
         "python-keystoneclient==3.15.*",
         "six==1.11.*",
         "peewee==3.8.*",
-        "pyyaml==3.*",
+        "pyyaml>=5.1.2",
         "prometheus_client==0.4.*",
         "gnocchiclient==7.0.*",
         "pyvcloud==19.1.1",