Replacement for nvm and other version managers.
requires:
sudo npm install -g
doesnt't work well with under nix-shell.
To install npm packages globally without sudo, change the npm global directory:
$ mkdir ~/.npm-global
$ npm config set prefix '~/.npm-global'
Add the directory to the PATH variable, so that your system knows where to find the globally installed modules:
echo "export PATH=~/.npm-global/bin:$PATH" >> ~/.profile