both Fedora and Ubuntu now use python3

Update bindep.txt to use python3-dnf for fedora.

Change-Id: Ie8cb9df95f6cbc164b3d8abde8f9e6468269138b
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

ansible/group_vars/all.yaml

@@ -12,6 +12,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 ---
+ansible_python_interpreter: /usr/bin/python3
+
 # windmill.virtualenv
 virtualenv_install_method: package
 

bindep.txt

@@ -7,7 +7,7 @@ libffi-dev [platform:dpkg]
 libselinux-python [platform:rpm]
 libssl-dev [platform:dpkg]
 openssl-devel [platform:rpm]
-python2-dnf [platform:fedora]
+python3-dnf [platform:fedora]
 python3-devel [platform:rpm]
 python3-dev [platform:dpkg]
 python-devel [platform:rpm]