[node.js] Create node.js virtual environment for test

Install package
$ sudo pacman python-pip
$ sudo pip install nodeenv

Create new environment:
$ nodeenv # define a name which you want
$ nodeenv /tmp/aaa

Activate new environment:
$ . env/bin/activate

Method 2:
$ cd /tmp/aaa
$ . bin/activate

Ref:

• Node.js virtual environment (sandbox) builder