Change to run only master branch

.travis.yml

@@ -5,15 +5,7 @@ os:
 node_js:
   - 'stable'
   - 'lts/*'
-before_script:
-  - 'npm install grunt-cli -g'
-  - 'export DISPLAY=:99.0'
-  - 'if [ ${TRAVIS_OS_NAME} = "linux" ]; then sh -e /etc/init.d/xvfb start; fi'
-  - 'sleep 3'
 script:
   - 'npm run lint'
   - 'npm run test'
-  - 'if [ ${TRAVIS_NODE_VERSION} = "stable" ]; then
-      grunt pre-build;
-      npm run test:e2e;
-    fi'
+  - 'if [[ ${TRAVIS_BRAHCN} = "master" && ${TRAVIS_NODE_VERSION} = "stable" ]]; then ./script/e2e-runner.sh; fi'