add a build script

Author: olix0r

gob/build.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+set -ex
+
+for svc in gen web word ; do
+  GOOS=linux GOARCH=amd64  go build -o $svc.linux_amd64 $svc/main.go
+  GOOS=darwin GOARCH=amd64 go build -o $svc.darwin      $svc/main.go
+done