Use jdk8 to run CI

.travis.yml

@@ -1,10 +1,12 @@
 language: java
 jdk:
-  - oraclejdk7
+  - oraclejdk8
 env: GOOGLE_APPLICATION_CREDENTIALS=$TRAVIS_BUILD_DIR/service-account.json
 before_install:
   - openssl aes-256-cbc -K $encrypted_99d8b304f94b_key -iv $encrypted_99d8b304f94b_iv -in service-account.json.enc -out service-account.json -d
 
-script: mvn test
+script:
+  - export GCLOUD_PROJECT=cloud-samples-tests
+  - mvn test
 after_success:
   - mvn clean cobertura:cobertura coveralls:report