nvm_on_a_mac.txt

Install 
$ brew update;
$ brew install nvm;
$ mkdir ~/.nvm;

Configure
This will make the "nvm" command available in your terminal
$ atom ~/.bash_profile; 

Add these lines right below your last "export" statement if one is already present
export NVM_DIR=~/.nvm
source $(brew --prefix nvm)/nvm.sh

Save the file in atom, then back in the terminal...
$ source ~/.bash_profile;
$ echo $NVM_DIR;

Using 
Show which node versions are currently in use and which are available
$ nvm ls;

Install an older version of node
$ nvm install 4.4.7;

Use a different node version
$ nvm use 4.4.7;

Alias 4.4.7 for va-web-2; "nvm alias <name> <version>"
$ nvm alias va-web-2 4.4.7;
$ nvm use va-web-2;

Helpful bash_profile command
function vaweb2_gulp_serve
{
cd ~/ventureapp/web;
nvm use 4.4.7;
npm install;
bower install;
gulp serve;
}