install gcloud and yarn

provision.workbox/main.sh

@@ -13,6 +13,17 @@ fi
 
 pip3 install --upgrade pip
 
+# install gcloud
+export CLOUD_SDK_REPO="cloud-sdk-$(lsb_release -c -s)"
+# Add the Cloud SDK distribution URI as a package source
+echo "deb http://packages.cloud.google.com/apt $CLOUD_SDK_REPO main" |
+    tee -a /etc/apt/sources.list.d/google-cloud-sdk.list
+# Import the Google Cloud Platform public key
+curl https://packages.cloud.google.com/apt/doc/apt-key.gpg |
+    apt-key add -
+# Update the package list and install the Cloud SDK
+apt-get update && apt-get install -y google-cloud-sdk
+
 # install docker-machine
 URLBASE="https://github.com/docker/machine/releases/download/v0.14.0"
 URL="$URLBASE/docker-machine-$(uname -s)-$(uname -m)"