Add CentOS to supported distro metadata

ekohl · ekohl · commit 4e412851dae4 · 2020-11-26T00:07:04.000+01:00
Red Hat is already supported and under Travis the acceptance tests run
on CentOS too.
diff --git a/metadata.json b/metadata.json
@@ -13,6 +13,13 @@
     "voxpupuli"
   ],
   "operatingsystem_support": [
+    {
+      "operatingsystem": "CentOS",
+      "operatingsystemrelease": [
+        "6",
+        "7"
+      ]
+    },
     {
       "operatingsystem": "RedHat",
       "operatingsystemrelease": [
