Update service account keys.

This now uses a key for the java-docs-samples service account, to better
track where these keys are used and test locally by downloading a key
for this account and running:

```
GOOGLE_APPLICATION_CREDENTIALS=~/src/java-docs-samples/service-account.json mvn clean verify
```

.travis.yml

@@ -1,10 +1,24 @@
+# Copyright 2016 Google Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 language: java
 jdk:
   - oraclejdk8
 env:
   - GOOGLE_APPLICATION_CREDENTIALS=$TRAVIS_BUILD_DIR/service-account.json GCLOUD_PROJECT=cloud-samples-tests
 before_install:
-  - openssl aes-256-cbc -K $encrypted_99d8b304f94b_key -iv $encrypted_99d8b304f94b_iv -in service-account.json.enc -out service-account.json -d
+  - openssl aes-256-cbc -K $encrypted_37a4f399de75_key -iv $encrypted_37a4f399de75_iv -in service-account.json.enc -out service-account.json -d
 
 script: mvn verify
 after_success: