Allow Travis to continue build if decryption fails.

Decryption of the service key can fail if Travis is building from a fork
instead of a branch.

Author: tswast

.travis.yml

@@ -15,10 +15,10 @@
 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_37a4f399de75_key -iv $encrypted_37a4f399de75_iv -in service-account.json.enc -out service-account.json -d
+  - openssl aes-256-cbc -K $encrypted_37a4f399de75_key -iv $encrypted_37a4f399de75_iv -in service-account.json.enc -out service-account.json -d \
+        && GOOGLE_APPLICATION_CREDENTIALS=$TRAVIS_BUILD_DIR/service-account.json GCLOUD_PROJECT=cloud-samples-tests \
+        || true
 
 script: mvn --batch-mode clean verify -DskipTests=false | egrep -v "(^\[INFO\] Download|^\[INFO\].*skipping)"
 after_success: