update stable branch build info

.travis.yml

@@ -10,7 +10,7 @@ after_success:
   - git config --global user.email "[email protected]"
   - git remote rm origin
   - git remote add origin https://thuhole:${GH_TOKEN}@github.com/thuhole/webhole.git
-  - CI=false REACT_APP_BUILD_INFO=$(printf "Travis%s" "$(TZ=Asia/Shanghai date +"%y%m%d%H%M%S")") npm run build
+  - CI=false REACT_APP_BUILD_INFO=$(printf "Stable%s" "$(TZ=Asia/Shanghai date +"%y%m%d%H%M%S")") npm run build
   #额，这里用了个骚操作来修复Service Worker在Precache CDN内容的时候index.html返回content-type text/plain的问题
   - sed -i 's/\/\/cdn.jsdelivr.net\/gh\/thuhole\/webhole@gh-pages-master\/index.html/.\/index.html/g' build/*-*
   - sed -i 's/\/\/cdn.jsdelivr.net\/gh\/thuhole\/webhole@gh-pages-master\/service-worker.js/.\/service-worker.js/g' build/*-*