Update travis file

.travis.yml

@@ -11,7 +11,6 @@ go_import_path: volcano.sh/volcano
 jobs:
   include:
     - stage: publish release
-      if: branch = master
       before_deploy:
         - export TRAVIS_TAG=$(git describe --tags)
       script:
@@ -21,13 +20,15 @@ jobs:
           script: make TAG=${TRAVIS_TAG} RELEASE_VER=${TRAVIS_TAG} release
           on:
             tags: true
+            branch: master
         - provider: releases
           api_key: $GITHUB_TOKEN
           file_glob: true
           file: _output/release/volcano-${TRAVIS_TAG}-${OSTYPE}.tar.gz
           skip_cleanup: true
           on:
             tags: true
+            branch: master
 notifications:
   webhooks: https://www.travisbuddy.com/
   on_success: never