Adding Registration helper. (#20)

* Adding Registration helper.

* Fixing formatting

sdk/eventgrid/app.go

@@ -0,0 +1,21 @@
+package eventgrid
+
+import (
+	"github.com/gobuffalo/buffalo"
+)
+
+// RegisterSubscriber updates a `buffalo.App` to route requests to a particular
+// subscriber.
+// This method is the spiritual equivalent of `App.Resource`:
+// https://godoc.org/github.com/gobuffalo/buffalo#App.Resource
+func RegisterSubscriber(app *buffalo.App, route string, s Subscriber) *buffalo.App {
+	group := app.Group(route)
+
+	route = "/"
+
+	group.POST(route, SubscriptionValidationMiddleware(s.Receive))
+	group.GET(route, s.List)
+	group.GET(route+"{event_id}", s.Show)
+
+	return group
+}