change default version nodejs code example

Example 1: node default version

# Install the version that you would like 
nvm install 6.1.0

# Set 6.1.0 (or another version) as default
nvm alias default 6.1.0

Example 2: change node version

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash