install gcloud and yarn

provision.workbox/user-setup.sh

@@ -9,6 +9,7 @@ curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | b
 export NVM_DIR="$HOME/.nvm"
 [ -s "$NVM_DIR/nvm.sh" ] && source "$NVM_DIR/nvm.sh"
 nvm install node
+npm install -g yarn
 
 if [[ ! -d ~/.ssh ]]; then
     mkdir -p ~/.ssh