更新nvm

在nvm的issue里某楼分享的方法 https://github.com/creationix/nvm/issues/127

#!/bin/sh

set -e

cd ~/.nvm

git fetch --tags
TAG=$(git describe --tags `git rev-list --tags --max-count=1`)
echo "Checking out tag $TAG..."
git checkout "$TAG"

source ~/.nvm/nvm.sh