that i can‘t build gh-ost successfullly

hi,
when i firstly build the gh-ost by "/build.sh" then comes the error :

```
Building macOS binary
go/logic/server.go:9:2: cannot find package "bufio" in any of:
/usr/local/go/src/github.com/github/gh-ost/vendor/bufio (vendor tree)
/usr/local/go/src/bufio (from $GOROOT)
/usr/local/go/src/github.com/github/gh-ost/src/bufio (from $GOPATH)
vendor/golang.org/x/text/transform/transform.go:12:2: cannot find package "bytes" in any of:
/usr/local/go/src/github.com/github/gh-ost/vendor/bytes (vendor tree)
/usr/local/go/src/bytes (from $GOROOT)
/usr/local/go/src/github.com/github/gh-ost/src/bytes (from $GOPATH)
vendor/github.com/satori/go.uuid/uuid.go:29:2: cannot find package "crypto/md5" in any of:
/usr/local/go/src/github.com/github/gh-ost/vendor/crypto/md5 (vendor tree)
/usr/local/go/src/crypto/md5 (from $GOROOT)
......
Build failed for macOS
Then it‘s stopped
my go env :

- [root@localhost gh-ost]# go env
- GOARCH="amd64"
- GOBIN=""
- GOEXE=""
- GOHOSTARCH="amd64"
- GOHOSTOS="linux"
- GOOS="linux"
- GOPATH="/usr/local/go/src/github.com/github/gh-ost"
- GORACE=""
- GOROOT="/usr/local/go"
- GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
- CC="gcc"
- GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build686716363=/tmp/go-build"
- CXX="g++"
- CGO_ENABLED="1"
```

so pretty wanner know the reason of my issues .Thank you !