fix(build): correct versioned doc site cname config (uber#3097)

Author: chasestarr

deploy-versioned-docs.sh

@@ -2,11 +2,13 @@
 
 set -e
 
+
 # deploy to now the versioned docs site
 FORCE_EXTRACT_REACT_TYPES=true yarn documentation:build
 now --scope=uber-ui-platform --token=$ZEIT_NOW_TOKEN --public --no-clipboard deploy ./public > deployment.txt
 deployment=`cat deployment.txt`
-cname="${BUILDKITE_TAG//./-}"
+version=$(echo $BUILDKITE_MESSAGE | cut -d' ' -f 2)
+cname="${version//./-}"
 curl -X POST "https://api.cloudflare.com/client/v4/zones/$CF_ZONE_ID/dns_records" \
     -H "Authorization: Bearer $CF_API_KEY" \
     -H "Content-Type: application/json" \