随着项目的增加，node的版本在很多时候成了各种bug产生的根本原因。我们需要使用nvm对node版本做管理和使用。
以下基本用法：
To download, compile, and install the latest release of node, do this:
nvm install node # "node" is an alias for the latest version
To install a specific version of node:
nvm install 6.14.4 # or 10.10.0, 8.9.1, etc
The first version installed becomes the default. New shells will start with the default version of node (e.g., nvm alias default).
You can list available versions using ls-remote:
nvm ls-remote
And then in any new shell just use the installed version:
nvm use node
Or you can just run it:
nvm run node --version
Or, you can run any arbitrary command in a subshell with the desired version of node:
nvm exec 4.2 node --version
You can also get the path to the executable to where it was installed:
nvm which 5.0