grepory: add main.go for gophercon

Change-Id: I47c01c7656e92b67c61a0bf5e640e0da95ae5af4
Reviewed-on: https://go-review.googlesource.com/48710
Reviewed-by: Jessica Frazelle <me@jessfraz.com>

grepory/main.go

@@ -0,0 +1,11 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("this is a fantastic contributor workflow.")
+}