作用：用户go get无法下载翻墙的时候的包，可以用gopm下载
gopm 安装
go get github.com/gpmgo/gopm
go install github.com/gpmgo/gopm
使用说明
NAME:
Gopm - Go Package Manager
USAGE:
Gopm [global options] command [command options] [arguments...]
VERSION:
0.8.8.0307 Beta
COMMANDS:
list list all dependencies of current project
gen generate a gopmfile for current Go project
get fetch remote package(s) and dependencies
bin download and link dependencies and build binary
config configure gopm settings
run link dependencies and go run
test link dependencies and go test
build link dependencies and go build
install link dependencies and go install
clean clean all temporary files
update check and update gopm resources including itself
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--noterm, -n disable color output
--strict, -s strict mode
--debug, -d debug mode
--help, -h show help
--version, -v print the version
exmaple
gopm get -g -v -u golang.org/x/tools/cmd/goimports
