Add script to check 'go fmt' status

gofmt.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+fmtcount=`git ls-files | grep '.go$' | xargs gofmt -l 2>&1 | wc -l`
+if [ $fmtcount -gt 0 ]; then
+    echo "run 'go fmt ./...' to format your source code."
+    exit 1
+fi