Update and rename Dyvil.dyvil to Dyvil.dyv

Updated the Dyvil Hello World program to the latest language version (v0.31.0).

d/Dyvil.dyv

@@ -0,0 +1,4 @@
+class Dyvil
+{
+	static func main(args: [String]) = print 'Hello World'
+}

d/Dyvil.dyvil

@@ -1,4 +0,0 @@
-class Dyvil
-{
-    public static void main([String] args) = println "Hello World"
-}