Adding upstream version 3.1.0+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

tests/yanglint/modules/moddatanodes.yang

@@ -0,0 +1,31 @@
+module moddatanodes {
+  yang-version 1.1;
+  namespace "urn:yanglint:moddatanodes";
+  prefix mdn;
+
+  container dnc {
+    leaf lf {
+      type string;
+    }
+    leaf-list lfl {
+      type string;
+    }
+    leaf mis {
+      type string;
+    }
+    container con {
+      list lt {
+        key "kalf kblf";
+        leaf kalf {
+          type string;
+        }
+        leaf kblf {
+          type string;
+        }
+        leaf vlf {
+          type string;
+        }
+      }
+    }
+  }
+}