add status codes and teapot example

examples/teapot.py

@@ -0,0 +1,13 @@
+from sanic import Sanic
+from sanic import response as res
+
+app = Sanic(__name__)
+
+
+@app.route("/")
+async def test(req):
+    return res.text("I\'m a teapot", status=418)
+
+
+if __name__ == '__main__':
+    app.run(host="0.0.0.0", port=8000)