Add test coverage for rows

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

tests/schema/fixtures/dashboard-0002.json

@@ -0,0 +1,15 @@
+{
+    "dashboard": {
+        "rows": [
+            {
+                "collapse": false,
+                "editable": true,
+                "height": "250px",
+                "panels": [],
+                "showTitle": false,
+                "title": "New row"
+            }
+        ],
+        "title": "New dashboard"
+    }
+}

tests/schema/fixtures/dashboard-0002.yaml

@@ -0,0 +1,5 @@
+dashboard:
+  title: New dashboard
+  rows:
+    - title: New row
+      height: 250px