update travis

Author: horike37

.travis.yml

@@ -8,6 +8,9 @@ matrix:
       env:
         - DISABLE_TESTS=true
         - LINTING=true
+    - node_js: '10.6'
+      env:
+        - INTEGRATION_TESTS=true
 
 sudo: false
 
@@ -17,7 +20,7 @@ install:
 script:
   - if [[ -z "$DISABLE_TESTS" ]]; then npm run test; fi
   - if [[ ! -z "$DISABLE_TESTS" && ! -z "$LINTING" ]]; then npm run lint; fi
-  - if [[ $TRAVIS_BRANCH == "master" && $TRAVIS_PULL_REQUEST == "false" ]]; then npm run integration-test; fi
+  - if [[ ! -z "$INTEGRATION_TESTS" && $TRAVIS_BRANCH == "master" && $TRAVIS_PULL_REQUEST == "false" ]]; then npm run integration-test; fi
 
 after_success:
   - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js && rm -rf ./coverage