update swig on windows

winx64/bin/swigwin-4.0.0/Examples/python/contract/example.i

@@ -0,0 +1,21 @@
+/* File : example.i */
+%module example
+
+%contract gcd(int x, int y) {
+require:
+	x >= 0;
+	y >= 0;
+}
+
+%contract fact(int n) {
+require:
+	n >= 0;
+ensure:
+	fact >= 1;
+}
+
+%inline %{
+extern int    gcd(int x, int y);
+extern int    fact(int n);
+extern double Foo;
+%}