Add yum-utils dependency for yumdownloader

Change-Id: I606b79117cec894e0d3275bc6890c7e45e98d8bd
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

bindep.txt

@@ -1,4 +1,9 @@
 # This is a cross-platform list tracking distribution packages needed by tests;
 # see http://docs.openstack.org/infra/bindep/ for additional information.
 
-python-pip
+libffi-devel [platform:rpm]
+libffi-dev [platform:dpkg]
+libselinux-python [platform:rpm]
+libssl-dev [platform:dpkg]
+openssl-devel [platform:rpm]
+python2-dnf [platform:fedora]

vars/RedHat.yaml

@@ -19,5 +19,6 @@ __diskimage_builder_depends:
   - debootstrap
   - kpartx
   - qemu-img
+  - yum-utils
 
 __diskimage_builder_package_name: diskimage-builder