Bump minimal version of ansible to 2.4.0

Currently 2.4.0 is the oldest release of ansible, everything later is
EOL. Update our meta data into include this and the platforms we
currently tests with.

Change-Id: Ice5b83492454123bb15cc7c22b5a23dd5bb90524
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

meta/main.yml

@@ -21,11 +21,15 @@ galaxy_info:
     comprehensive test system including Jenkins and Zuul.
   company: Red Hat, Inc.
   license: Apache
-  min_ansible_version: 2.0
+  min_ansible_version: 2.4
   platforms:
-  - name: EL
+  - name: Fedora
     versions:
-    - 7
+    - 27
+  - name: Ubuntu
+    versions:
+    - 16.04
+    - 18.04
   categories:
-  - cloud
+  - system
 dependencies: []

requirements.txt

@@ -1 +1 @@
-ansible>=2.0.0,<2.4.0
+ansible>=2.4.0